This boss is pretty simple, as there's only 3 things you really need to look out for. First off he spawns 2 high HP adds that spawn at the entrance of the room at the gates. These adds must be dealt with immediately, as they'll go for the healers of your party if not properly dealt with.
Firebombs: he casts firebombs throughout the instance that will stay on the floor for quite awhile -- simply avoid these. Also if you're tanking the boss or adds, be sure to lure them away from the firebombs, so that melee DPS will have an easier time fighting the adds/boss.
Lastly the boss does an AOE missile attack that damages party members around him. There will be an alert on your screen notifying you that the boss is ready to launch his missiles. Melee DPS simply need to get out of range when he does this. Note, a red circle AOE indicator will appear right before the missiles drop; however, players will not have enough time to get away -- therefore it is best to move out of the way when you get the alert message rather than waiting for the red AOE indicator to show up.