C&P from here:

Lords

Sorcerer-Prophet
The only lord option in the army which should be considered a very tough wizard lord rather than a magic using combat lord. He comes with Blackshard armour and a Darkforged weapon making him fairly decent in combat, especially mounted on a Taurus with Blood of Hashut. For a defensive lord use the Talisman of Preservation and the Enchanted Shield along with a Potion of Healing. In paying for a magic weapon you lose his Darkforged weapon so it probably not worth it. An alternate use can be sitting back with the war machines using a long range lore, but Hobgoblins and Bull Centaurs may struggle without his leadership.
Advantages: Very tough for a wizard lord
Disadvantages: Slightly weak for a combat lord, expensive

Great/Bale Taurus: A good choice for an offensive lord especially combined with the Lore of Fire where two of the spells can be used to heal the Taurus. The Bale Taurus upgrade give an extra +1 toughness and +1 wound in addition to a strength 4 flaming breath attack, although it is quite expensive.
Advantages: Good combat ability, can regenerate wounds, breath attack
Disadvantages: Probably not as good as other armies lord mounts

Lammasu: The only access to the Lore of Shadow in the army. Negates Magic weapons in base contact. Good choice for a defensive lord as any enemy character won’t have his magic weapon giving the Sorcerer-Prophet a good edge.
Advantages: Extra levels of shadow magic, can reduce enemy character ability
Disadvantages: Fairly expensive

Heroes

Daemonsmith Sorcerer
Quite a tough hero level wizard with engineer abilities as well. A level 1 using the lore of fire with a charmed shield and dispel scroll is an effective magic boost and war machine baby sitter. His reroll ability is excellent and he can look after two war machines adequately in addition to defending them from skirmishers and the like(equip with naptha bombs for a sneaky stand and shoot). He comes with a 4+ save and a +1 strength magic weapon so even ethereal units don’t scare the war machines. However being so far from the battle means that the lore of fire is the better option as metal and death are relatively shorter ranged lores. He is an excelent carrier for the Chalice of Blood and Darkness which saves your Prophet's item allowance for defence.
Advantages: War machine reroll, war machine defence
Disadvantages: Restricted in magic lores

Dark Castellan
One of the best heroes in the game with a stat line which rivals many lords and a higher magic item allowance than any other hero. As a battle standard bearer with the Mask of the Furnace, shield and a great weapon he will turn a unit of Infernal Guard or Ironsworn from very tough to almost immovable. Making the unit Stubborn means you can deploy in two ranks to make the most from your ranged weapons and not worry about losing a round of combat. A good defensive combo with his 75 points of magic items is the dawnstone and trickster's helm, making the enemy reroll successful wounds along with a rerollable 3+ save. He could also use an Arabian carpet and fly in to weak units to hold them up.
Advantages: Stubborn, high magic item allowance
Disadvantages: Will often have to take challenges from lords.

Hobgoblin Khan
The cheapest hero available who can fill a few roles. He can be used as a cheap addition to a unit of cutthroats or mounted on a great wolf to assist a unit of Wolf Raiders. As a lone mounted Khan he can be used to bait and redirect enemy units and is more reliable than a unit of Wolf Raiders as he does not suffer animosity. He can also be used to hunt war machines and hero wizards quite effectively. For a nasty surprise equip him with the Terrifying Mask of Eee! And charge him into a low leadership unit or the Ruby Ring of Ruin and move him to where it can be really effective.
Advantages: Very cheap, versatile
Disadvantages: Don’t expect much

Bull Centaur Taur’uk
Possibly the toughest hero in the game who can hold up units single handily. As standard will have 4 wounds, toughness 5 and a 3+ armour save which can be upgraded to a 1+ easily with Blackshard armour and a shield leaving 50 points for a ward save or similar, a good choice is the dawn stone for a rerollable 1+. With a great weapon he has 4 strength 7 attacks making him very good at challenging enemy characters, especially if equipped with the other trickster's shard to negate enemy ward saves. As you have to take him with a unit of Bull Centaur Renders he can start off within the unit but move/charge out of it on his own if the situation dictates. This increases his protection against warmachines if you have a unit of 5+ as he'll get a look out sir roll.
Advantages: Extremely tough, very hard hitting, monster assassin
Disadvantages: Must include a unit of bull centaurs, expensive

Core

Chaos dwarf Infernal Guard
Best taken in units of between 20 and 30 although smaller units of 10 or 15 may also be useful in the right situations. Full command is worth paying for but the Musician and Champion can be dropped with much worry. Banner of Eternal Flame is cheap and very effective when combined with Ash storm. Razor Standard is effective against heavier armoured units.

Hand Weapon & Shield: Standard equipment which confers 3+ 6++ armour save in combat making them amongst the most resilient infantry in the game. Combine with a Castellan battle standard and you have an excellent anvil unit which will not flee easily.
Advantages: Very cost effective for your 25% core.
Disadvantages: Low damage output.

Great Weapons: The cheapest weapon upgrade bringing the unit’s strength up to 6 at the cost of bringing the armour save in combat down to only 4+. However with toughness 4 they’re still a match for most. The always strike last with great weapons doesn’t matter that much as a Chaos Dwarf’s initiative is low anyway and the extra strength really gives the unit some punch. A good use is as a small unit of 10 as a flanking unit after your anvil has pinned the enemy. Can be effective against small, high toughness units such as monstrous infantry.
Advantages: High strength good for adding damage to stalemate combats.
Disadvantages: Loss of armour save and relatively high cost of weapon.

Fireglaives: Similar in combat to great weapons but with an 18” ranged weapon. Good against medium armoured targets with the Armour Piercing special rule and strength 4. Can be devastating against medium armoured toughness 3 cavalry. Use an Overseer with a pistol or Naptha Bomb to ensure the unit fires at short range in a stand and shoot reaction.
Advantages: Unique to Chaos Dwarfs and can catch enemy unaware if they think they’re charging just a ranged unit.
Disadvantages: Short range means not many rounds of shooting. Expensive and can be an easy target for templates.

Hailshot Blunderbusses: Most expensive weapon option but the unit still has hand weapon and shield for close combat. Random multiple shots does make it slightly unreliable but has a lot of potential and is very effective against lightly armoured, low toughness troops. Needs to be used in units of 20+ to get the to-wound reroll for maximum efficiency and casualties needs to be considered. The unit also needs to be deployed with a long frontage (Two ranks of 10-15) which will make them vulnerable in combat without a Castellan. A unit of 30 in two ranks including a Battle Standard Bearer will be a powerful unit which is hard to defeat making it useful if playing a points denial game.
Advantages: High potential for devastating damage. Still very effective anvil combat unit.
Disadvantages: Very short range. Extremely expensive unit vulnerable to templates and magic.

Hobgoblin Cutthroats
Only low point unit in the army. Can be surprisingly effective in hordes while close to the General and Battle Standard but susceptible to animosity when not near a Chaos Dwarf unit. Full command is cheap and effective for a combat unit which is best taken at 30+ in hordes. 20+ units with bows can be effective. Throwing knives can be an unexpected surprise to a charging enemy.

Hand Weapon: Basic and cheapest option. Can occasionally be effective as a support or flanking unit alongside a unit of Infernal Guard. Useful to send ahead as a throwaway unit causing distractions as it will not cause panic amongst anything but other Hobgoblins.
Advantages: Cheap throwaway unit.
Disadvantages: Fairly ineffective.

Hand Weapon & Shield: For half a point extra per model it brings the save to 5+ 6++ making them a noticeably more resistant in combat. Can be used as a risky anvil if the General and Battle Standard are nearby.
Advantages: Still a cheap throwaway unit but more resilient.
Disadvantages: Still fairly ineffective.

Additional hand weapons: For half a point extra per model it effectively doubles their combat ability. Used in a horde it has good potential to actually win against average enemy infantry with massed attacks.
Advantages: Cheap unit with a huge number of attacks.
Disadvantages: Will still die in droves so don’t overestimate them.

Bows: Cheapest and longest ranged unit other than war machines. Good to thin out enemy units and then as a throwaway unit to distract the enemy. Can also take shield to make them a more resilient support unit.
Advantages: Cheap massed ranged weapon.
Disadvantages: Fairly ineffective in combat.

Special

Chaos Dwarf Infernal Ironsworn
Essentially a buffed up unit of Infernal Guard with Ensorcelled hand weapons and shields. Magic weapons with +1 strength and +1 weapon skill combined with their resilience makes them a tough unit which can also dish out some effective attacks. They should be able to stand up to any enemy charge and hold them in place, slowly witling down the enemy numbers. In a battle of attrition the Chaos Dwarfs will win. Razor Standard is an effective magic banner giving a total -3 armour modifier.
Advantages: Extremely good at not dying.
Disadvantages: Relatively expensive.

Bull Centaur Renders
Extremely tough Monstrous Infantry with good weapon options which make them quite versatile. With toughness 5, 3 wounds and a 3+ armour save as standard they do not die easily. An excellent choice as an anvil unit to hold a low strength enemy in place, anything strength 4 or under should struggle to cause noticeable damage. They can also be used as a mobile, hard hitting unit to hunt war machines and small, fast units. Full command is generally always worth it with the Gleaming Pennant or Banner of Discipline if the unit is going to be away from the General and Battle Standard. Bull Centaur Renders are monstrous beasts and therefore treat all weapon options the same as infantry on foot.

Hand Weapon: The cheapest option with low damage output but can potentially be good with an augment spell like Flaming Sword of Rhuin combined with Ashstorm on the enemy you will be dishing out some decent damage. Use a small unit against war machines, skirmishers, small support units.
Advantages: Quite cheap, relatively speedy and very tough.
Disadvantages: Not very hard hitting.

Hand weapon and shield: Gives them a 2+ 6++ save in combat. Combined with their wounds and toughness this makes them unbelievably resilient. A good choice for an anvil unit of 6 to hold the enemy in place although they still need augmenting for any real damage output.
Advantages: Still pretty cheap, relatively speedy and extremely tough.
Disadvantages: Still not very hard hitting.

Additional hand weapon: A cheap upgrade which makes a noticeable increase in damage output. Quite similar in use to the hand weapon option although they will be better against low toughness infantry, especially useful for a flanking manoeuvre.
Advantages: More attacks, relatively speedy and very tough.
Disadvantages: Still low strength attacks.

Great Weapons: Most expensive weapon option and you are striking last but as you are only initiative 3 your targets will probably have higher anyway. Bringing the strength up to 6 makes them more useful against heavy infantry, you'll likely be wounding on a 2+ and giving -3 armour save. They can also give other monstrous units and monsters a hard time.
Advantages: High strength attacks, relatively speedy and very tough.
Disadvantages: Low number of attacks.

Spear and shield: Needs to be taken in large units with three ranks to make use of the spears. But with a 2+ armour save and extra attacks it makes them an amazing anvil unit that can grind the enemy down, move them in front of any enemy and take the charge without a flinch.
Advantages: More attacks, relatively speedy and extremely tough.
Disadvantages: Low strength attacks. Needs to be a large, expensive unit.

K’daai Fireborn
An unstable unit that needs to be used quickly and carefully but with awesome potential. Where the Bull Centaurs focus on defence the Fireborn are more about offence. With a toughness of 4 and only two wounds the unstable and burning bright rules can make the unit very unreliable. However they are unbreakable, have a 4+ ward save and the enemy must reroll successful wounds, this makes them tough for the opposition to wound. With the blazing body auto hits and strength 5 they can cause damage, but are best taken in large units to cover losses(on average you will lose one or two per game from burning bright). Units of 6 or 9 are best used against low toughness troops; combine with Ash Storm to really make the most of them.
Advantages: Decent amount of attacks, unbreakable
Disadvantages: Expensive and can burn themselves out.

Magma Cannon
Unique to the Chaos Dwarfs this flaming template cannon has excellent range and damage. Strength 5 and D3 wounds makes it excellent against any large multi-wound unit such as monstrous infantry. When made Hellbound it is exceptionally good against ethereal units. With a Daemonsmith reroll on the scatter distance it becomes very accurate.
Advantages: Cheap, high potential damage output
Disadvantages: Vulnerable (without Hellbound)

Deathshrieker Rocket Launcher
The cheapest war machine available which is similar in effect to a mortar, this has two different rockets to fire. The standard rocket is flaming strength 3 which causes panic. It uses the large 5” template but if the shot is not on target you gain a second roll on the artillery dice towards the nearest unit, although this only uses the small 3” template. Combined with the Daemonsmith reroll this makes it extremely accurate. The Demolition rocket is strength 8 with D6 wounds but only hits one target and doesn’t get the extra roll if it misses. However along with the Daemonsmith reroll this can be used to snipe monsters and war machines. Two of these sharing a Daemonsmith are very effective.
Advantages: Cheap, extremely accurate and versatile
Disadvantages: Vulnerable (without Hellbound)

Iron Daemon War Engine
A very tough but unwieldy unique unit. With 7 wounds and toughness 8 with a 3+ armour save it’s one of the most resilient units in the game. If you can manoeuvre it to charge an enemy unit it will hold them up for the entire game slowly grinding them down. The cannonade is particularly effective against cavalry and monstrous infantry although it’s short range and front firing can make it hard to get the target you want. For a small cost this can be replaced with a skullcracker which will double its thunderstomp and impact hits however it’s not as versatile and will need to be used well. Best option is to send it across the board at a diagonal and hope to hit something good. Both options however can be easily held up by flyers and anything immune to its grinding attacks, if they charge it will only have it's three crew attacks.
Advantages: Extremely tough, hits hard on the charge (really hard with skullcracker)
Disadvantages: Expensive, hard to manoeuvre, can be easily held up by some cheap units

Rare

Hobgoblin Wolf Raiders
The only fast cavalry unit available in the army which is quite cheap and very manoeuvrable. Units of 5 an be used as effective redirectors, fleeing from enemy charges which won’t cause panic in anything except other Hobgoblins. They can also be used to harass war machines although their animosity can make them unreliable. Full command is worth it but a musician is essential for manoeuvring. The cowardly despoilers rule makes them effective flank charges giving an extra +1 combat resolution. Use in tandem with Bull Centaurs to keep their animosity in check.

Hand weapon: Basic cheap option, best if being used as a redirector or sacrificial unit.
Advantages: Very cheap, very fast
Disadvantages: Animosity, low leadership

Shields: Lose the fast cavalry rule making them less reliable, however when used with a spear in a larger unit of 10 or 15 they can be used as medium cavalry with a 4+ save. With the larger unit size the effects of animosity is lessened and then the +1 to hit can be effective. Wait to fail your animosity with a 6 then charge.
Advantages: Slightly more resilient.
Disadvantages: Less manoeuvrability, Animosity, low leadership

Spears: Cheapest weapon upgrade providing a bit of extra punch for flanking or war machine hunting. With their awesome charge range they can be a real threat to war machines.
Advantages: Cheap flanking ability, low cost
Disadvantages: Animosity, low leadership

Bows: Probably not very useful in most situations, 5 bowshots won’t do much damage. Best to be used against small weak units or single characters hiding where they think it’s safe.
Advantages: Getting a few bow shot in the right place
Disadvantages: Animosity, low leadership

Dreadquake Mortar
Extremely powerful war machine with very long range. The Quake! Special rule can halt units in their tracks which can be very effective firing on a unit that would charge you in their turn, if they charge they have to take the dangerous terrain test if they don’t then they can be charged next turn. Without a slave Ogre there is a chance it won’t fire every other turn, but with the Ogre it will fire every turn and also gain an extra 3 wounds in addition to extra combat ability making it quite resilient. With Hellbound it will have 7 wounds and toughness 8! However without a Daemonsmith nearby it can suffer from bad misfires. Excellent against large blocks of high toughness troops and monstrous troops. I can also be used against large monsters and war machines with its strength 10 centre hit and D6 wounds.
Advantages: Devastating power and range, can slow enemy advance, very tough
Disadvantages: Bad misfires, needs Slave Ogre for best results

K’daai Destroyer
The most expensive unit in the army with an unbelievable potential damage output. With a possible 9 attacks, blazing body auto hits and thunderstomp it can take out entire units in single turns. Movement 9 allows you to get it exactly where you want. With 6 wounds and toughness 6 and a 4+ ward save it is hard to wound in combat, combine this with the blazing body rule where the enemy must reroll successful wounds this means low strength (5 or below) attacks will really struggle to hurt it. As powerful as it is, poison will wound it effectively and anything that lowers its toughness will really hurt it so be wary of the Lore of Shadow. It can also be vulnerable to units with 2+ fire ward save which will hold it up all game and be aware of being baited out the way due to it's frenzy rule.
Advantages: Massive damage output, extremely tough, unbreakable
Disadvantages: Expensive, burning bright and unstable make it unreliable occasionally, can be held up by lone characters with fire wards or ethereal units

Hellcannon
Currently quite cheap but will likely see a reduction in power with the new Warriors of Chaos army book due to be released soon. Its template weapon is very effective and it has monster characteristics making it very able to defend itself. Excellent at defending a flank on its own however it can go very wrong with a misfire.
Advantages: Powerful template, very tough for a war machine, Unbreakable
Disadvantages: Occasionally Rampages

Chaos Siege Giant
Only a bit cheaper than the K’daai Destroyer and generally not as powerful, however it can be great as a monster hunter although its random attacks can make it unreliable. It can also be used to take out tough characters as many of its attacks allow it to select a target and ignore toughness and armour saves. It is also quite well armoured against shooting attacks allowing it to get to where you want it. It can be very effective in siege battles using scaling spikes to easily take down buildings and walls and becoming a ladder if it dies.
Advantages: Monster hunting, character eating, building crushing
Disadvantages: Unreliable, sometimes falls over