First 6 bosses on Heroic are pretty easy:
Short version:
Hellfire Assault: Bloodlust boss to 50% then Terror > Vehicle > Hulk > Felcaster > rest of adds. Tell everyone this is a single target fight. Collect loot.
Iron Reaver: Do not stand in fire, Ranged Stand slightly separated and All move to left as group when she preps to send fire. Tanks run out with artillery. Don't chase boss to tanks. Kill bombs, don't get run over by robot during charge. Collect loot.
Hellfire High Council: 1 Tank take Dia off to side, other tank holds Gurtogg and Blademaster. Burn Gurtogg til dead, Burn Blademaster til dead, Burn Dia til dead, bloodlust at 40% on Dia. Don't stand on your buddy with reap. Collect loot.
Kilrog Deadeye: Melee on left side of boss, tank on right side, Ranged on right side of room. Mages (If arcane have slow glyphed), Hunters learn were you put your concussive shot button. Blood pacts runs to back middle of room. NOONE should be in that path, if so, kick them from raid. Kill bloods, Slow adds and kill them as ranged. Send in 1 healer and 2 dps. Collect loot.
Kromok: Learn /range 4, All stay in very small pack on same side for grasping hands. Kill hands quickly! Kill tanks hand quickly. Avoid slow moving raid mechanic. Have intelligent group move empowered runes together. Avoid slow moving raid mechanics! Burn down boss, collect loot.
Gorefiend: Spread out. If you go in do your job and get out in last 5 seconds. Don't stand in bad stuff. Move to edge of room with soul fissures. Healers keep CDs for Feast of Souls. Add priority is Caster, Big Guy, Constructs unless your being chased by construct.. In which case, it's construct, caster, Big guy, other peoples construct. Tell your raid adds have priority. During Feast of souls everyone pile in one place, tanks catch souls, Burn down boss, use alot of healer CDs. Collect loot.