Here are the screens from our last Naxx raid!
Not a very hard fight. Keep hots on the MT, raid heal a bit, avoid blizzard and hide behind an iceblock.
Not much to do in the start of the fight if DPS is good. Stay 10 yards apart in the second phase and avoid standing in purple circles on the ground. Other than that hope that your mind controlled players are effectively crowd controlled, that melee and the MT know how to move and keep those heals going.