Dec 2nd 2008 12:10AM I haven't read all the comments here, but from what I've read so far I see most ppl ahve covered all the important basics. 2 things I haven't seen yet:
1) If you are one of the classes "blessed" with a new knockback ability, take it off your toolbar. These are for soloing & your tank will be very frustrated if you knock everybody around after he positions them just right. Trust me, your tanks will thank you for not using it if they've *ever* encountered somebody who does.
2) With the group make-up described, you have 2 melee dps fighting with your tank. For all that is holy, stand behind the boss. If the boss has a tail, stand at his side. Do not stand in front of teh boss with the tank. A boss can parry an attack from anybody in front of him. That parry equals more attacks on your tank, which equals more heals on your tank which equals less heals on everybody else. While it may not cause a wipe, your healers will appreciate you making their jobs a bit easier.
If you would like to know the math behind this, it is said here better than I could ever write myself: http://elitistjerks.com/f47/t15596-melee_combat_mechanics/
Also, it helps if you've looked at the boss drops ahead of time, to know what you need as an upgrade. Saves time. & bring an enchanter, no sense vendoring BoP items nobody needs if you can get some mats for enchants instead.