Rough boss layout for HFC if you hadn't seen it yet-
Hellfire Assault and Iron Reaver are the first 2, Kormrok is optional (but has tier helms) and then after Gorefiend you can scatter around. I've seen conflicting lists of preferred order so where we go may just depend on our raid strengths and such.
Hellfire Assault Wowhead fight description
Sounds like: add control/priority/burst
Iron Reaver Wowhead fight description
Sounds like: Stay out of the bad, avoid spread and wear it down
Read the fights or watch videos and don't be like me and forget them 5 minutes before raid. :D
I am always a strong advocate of 'read the overview, 2 minute plan, test pull, full discussion'. That way we know what Kormrok's hands look like or how hectic Iron Reaver's flying phase. Nothing like learning by doing
Some Hellfire Cache Mission Facts:
They are naval missions, that begin appearing once you get a level 2 shipyard
They start a step down from what you were CLEARING last tier (We did heroics, so we get normal caches at the start)
Assumption is 27 lootable kills to get the next rank (2 full clears + 1)
There are a number of missions/counters needed for the missions
(You can get screwed like me and get a bad mission. I need a carrier to full counter and I need a lvl 3 shipyard to get access to those [25 treasure missions to upgrade...yay])