I have no idea if this is correct or not, but I'll ask since I'm also wondering how to work my CD-R in linux. Could you not just moung the CD-R drive, and copy files to it just as if you were copying files to any other directoy? I'm thinking you'll probably have to issue some sort of command to format the disc or such before you can work with it though.
But then there comes the other problem about burning direct copies of CDs and converting mp3s to wavs. Does Linux come with any sort of CD-Burning utility that can be used in X or anything like that?