I'm new and I love music!

Hey all I'm new to the forums :(. Ok well heres nothing. My whole family is in the music stuff. My parents are musicians and my brother is an audio engineer. My dad composes music with his computers and plays the trumpet. My mom works in newark in asynthphony orchestra. Ok well I use GarageBand on my PowerBook G4 to try and compose music. I feel that it's not enough and I wanted to go a little further. I was thinking of buying some sound modules for what I wanted to create. I really am sort of new to modules and stuff so I'd like some help. The reason why I am getting more sounds is because the ones that are built in the program really stink. I would like to just go out and make abstract sounds and songs. I'd give you some song links to what I like but I don't have a proper ftp site...