How to post MP3's?? HELP!

Come on we all know our favorite bloggers do this: stereogum, brooklyn vegan, WFMU, Hype Machine, (insert yours here)
so why can't I? I consider myself computer literate...yet I don't know how to post Mp3's! someone help a kid out!

seriously. you would make me a happy kid

"I'm just a happy kid stuck with the heart of a sad punk."
matthew caws