You download cool edit off a torrent site or off Limewire. It's pretty basic and easy to use. To get going you're going to need at least.. a microphone, some sort of pop filter, you can make your own actually by bending a metal clothes hanger and using some pantyhose or something. You'll need headphones and some beats. You can get free beats off SC or you can pay for some OR if you're just fucking around and not serious about putting the tracks you're using on a mixtape you can download random beats off Limewire and shit as well.

Anyways.. good luck.