Hellbreach DPS Perspective

I've now run the first LFR wing of Hellfire Citadel on several toons - a Death Knight, Rogue, Mage, and Warlock, in addition to the tanking Paladin. Admittedly, on at least two of those characters as I recall, I came in on the last boss, but I've got a good idea of how the fights go.

Hellfire Assault:

The first fight is, sadly, a pretty dull affair. The only non-boss boss fight I remember really liking was the Icecrown Gunship Battle, with the awesome jetpack mechanic. On LFR especially, this fight's basically an AoE fest - though killing the warlocks who do Metamorphosis will help reduce damage to the raid.

As soon as one of the Fel siege engines goes down, be sure to grab the ammunition box - chances are someone else in your raid will get it first, but you don't want to be in one of those situations where everyone figures someone else is doing it. This is of course how your end the fight, so it's a high priority.

Iron Reaver:

This is the real raid-killer of the wing - not because the mechanics are particularly difficult to deal with, but because it's a fight that requires the raid to spread out, and in the uncommunicative manner of LFR, your healers will probably not be very well-distributed to cover everyone.

The Reaver also moves around a lot, so you'll need to constantly readjust, making sure you're in range of the Reaver and also not crowded up with your allies.

Finally, spend all your "not standing in fire" attention on the air phase killing bombs. It's your only real job (again, other than not standing in the fire) and will save the raid a bunch of pain.

Also, sometimes DPS gets hit with Artillery. Be sure to run away and, if you have one, pop a survival cooldown before it hits you.

Kormrok:

If you pull it off well, you can skip the green-pool phase entirely just by killing the boss before he gets to it.

On the orange pool phase, be sure to run away from the tank when they get their debuff, as they won't be able to run away from you. Also, pop the exploding runes before they hit the raid - the faster you do, the less damage you'll take.

Purple phase will be fairly simple - just take the effort to dodge the waves. You might have to drop what you're doing in order to do this, but it's better to live longer with slightly lower dps than to die and produce no further damage.

Last Note on Loot:

As with all the wings in LFR HFC, the final boss of each wing drops gear that's ten item levels higher than the other bosses, so if you're planning on spending your bonus rolls in LFR, you're best served saving them for the last boss of the wing (the set pieces also drop off these bosses.)