BON is a huge battle between a 40 person raid and Tritanta.
Have your tanks secure agroo for 10 seconds. One this happens ,Let loose on DPS with out regard. If he changes target from any Tank, cease DPS imediatly. One aggro is regained,continue the process. If someone dies,he ressurects them as Zombies that the computer controls. Have a hunter set on killing the zombies. About half way through,a ramdom 25 people are killed. These people are not ressurected as Zombies. Kite him left and right,back and forth until everyone is back. He can't attack while he moves. At a 1/4 of his health he flys up trys to run. Mount the skeletons gryhsons provided and battle him in the air. Everyone lay on as much \damage as possible. When he has 100,000 thousand health left,he starts killing at random,once every ten seconds.
Congrats!!! you hve beaten the toughess encounter in WoW.