Congrats, now its time to learn more about your WRX.
http://www.spdusa.com/ <-- A must, info on your car.
http://www.NASIOC.com/ <-- An enthusiest/owners club, priceless info.
And once you start browsing around nasioc, you're gonna get more links anyhow.
I'll start you off with one:
http://www.vishnutuning.com
-T