When the league is formed I will send you the league name and password to you PM inbox. After that, all you have to do is sign into Live and click "My Leagues." The games for each week are launched from the League Lobby via your Xbox. It's real simple.
I am sure Shush will provide you with the league information. To start, you will see your schedules once in the league, and from there, I am sure Shush will post an AIM list or something similar. Then you go to the online league lobby on the XBOX to play the game.
Probably a good idea. For those that are uncertain how this whole operation works, you can join any public league. HM3, you can also ask Jman to guide you.