NCAA Football 07, NSMB, Chromehounds, and 360 Software Tops Sales in July

XBOX Live is just the subscription service; there really isn't anything physical to add. There is an ethernet port on the back of the system for connecting to whatever Internet you have (or for connecting to a wireless adapter if you need to connect to a wireless setup). As long as it is a broadband connection that's all you need.

The basic service is free; includes the ability to download demos and trailers and stuff and any updates to the system (along with backwards compatibility updates). The 50 dollar yearly subscription will allow you to play online games and get all the features that come with that depending on the game.

You can just buy a subscription card for 50 bucks, or, in most retail stores, a 60-70 package that includes the card, and usually a game or points for the Marketplace (where you can buy Arcade games and downloadable content for your games).