Does Myth support Mp3 audio? I have some cds that need burning and I have not been able to find some for Linux as of yet.
Yes, Mythmusic can play MP3-files. I think it does by default, because MAD Mp3 decoder plugin is required for Mythmusic to install. Ref.: http://www.mythtv.org/wiki/index.php/MythMusic
As for burning CDs, you mean creating an audio CD from MP3-files? I recommend K3b.