Welcome to XBA, enjoy your stay.
Points of interest include:
If you feel like sharing the epic reasoning behind your Gamer Tag, feel free to visit this thread, there are some interesting reads there I might add:
http://xboxamerica.com/threads/Whats-behind-YOUR-Gamertag/page/1
Meta's Ultra Waffle Thread, for the easy 1000 games
http://xboxamerica.com/threads/Metas-Ultra-Waffle-List-10xp/page/1
Top Dogs' Xbox America Trade In Center, for games you don't want anymore
http://xboxamerica.com/threads/Xbox-America-Trade-In-Center
Top Dogs' Waffle List 2.0 after your blue in Trade Thread, for games you just want to pass around the community.
http://xboxamerica.com/threads/Waffle-Order-20/page/1
There are also the weekly Gamerscore Competitions, and multiple lists in the threads, like the Game Completion List and such.
And the Events for any game you may want to play, or make an Event for.