Rocketry is all about fun and learning. Thrust optimization, structural integrity, CP, CG, minimum thrust, Newton-Seconds, rails, altimeters.....
Do these terms sound foriegn? Not to worry, it sounds more complicated than it is.
Here are some links to explore to get all the information you could want and more about rocketry.
Rocktry Online's-InfoCentral
FlyRockets.com