if I wanted to make a deck with as many Rohirrim as possible which expansions should I get?

it thinks Rohirrim should be Hiroshima lol

Voice of Isenguard helps a lot ... But there are rohan cards in many AP and lots of them are important for rohan decks

sorry bad at abbreviations whats AP stand for?

AP = Adventure pack.

The first AP cycle (Hunt for Gollum etc.) contained a lot of Rohan cards and Rohan was probably the most powerful archetype at that time. Combine those packs with Voice of Isengard and you will have most of the cards.

is there somewhere where I can find a list of all the packs in each cycle?

http://www.boardgamegeek.com/boardgame/77423/the-lord-of-the-rings-the-card-game

Go here to research cards:

http://hallofbeorn.com/Cards/Search?CardType=Player&CardSet=Any&Trait=Rohan.&Keyword=Any&Cost=-1&Sphere=None&Unique=False&Sort=None&Random=False

If you follow this link, it will default to showing all player cards with the "Rohan" trait (basically heroes and allies). For events and attachments, you'll need to do some browsing since most of those cards do not have traits and many of the good ones for Rohan wouldn't mention Rohan by name anyway.

At least you can see the name of the AP next to the card name and you can change the filter at the top to look at whichever AP you want.

Hopefully, this will help!

If you want to play Rohan tactics, you should get Morgul Vale too

Voice of Isengard and A Journey to Rhosgobel give you 2 heroes working well with Rohan and also some useful cards.

There you go m8 http://www.cardgamedb.com/index.php/index.html

If you jump ahead and buy the cards, Feonix (one of the developers) posted a fun Rohan deck that many of us have tweaked around.

http://www.fantasyflightgames.com/edge_news.asp?eidn=4651

But if you go through the packs in order you can still get a good questing Rohan deck working with the first cycle.