Assuming you have a decent sound card, go from stereo out (RCA) to line in (1/8" phone cable). You will need a Y cable to do this. Then you will need some software to record with. I use Soundforge. After that, you can convert it to whatever format you want, but you will need to find a file converter somewhere on the net. I hate real audio, and I would suggest using MP3's, but it's up to you.
-Nilbog