First off, congratulations on this fantastic purchase, youll love the 360!
As for your first question; battery packs are way easier and cheaper then AA batteries. You should get the Quick Charge Kit if you have two wireless controllers. This set includes 1 rechargeable battery so you should get a seperate one extra. Will cost you like $40 but you can recharge them whenever you want, even when your 360 is turned off.
As for games; if you are a hockey fan you should get NHL 10 or maybe 09 cause thats probably half the price. Very good games and really fun with local multiplayer.
As for other games you can probably pick up some great cheap games like Crackdown, Mass Effect 1 or 2 or both, Ninja Gaiden II and several JRPGs like Tales of Vesperia, Lost Odyssey and Infinite Undiscovery. Plus, you should definitely check out Xbox Live Arcade cause there is lots and lots of great cheap games there!
You aint found shit!
