i need some sound files

i was wondering if some one could give me a file or tell me were i can get a sound file of:
1. a sniper shot
2. a big exposion sound
3. background music that would sound good for a map like halo

if u could give me or tell me were to get it, that would be great *i will put u in the credits*

do a internet search on .wav files(or watever)