Here's 2 for you:

1) MediaCoder - An open-source program that's capable of transcoding among different audio/video formats. Excellent for advanced users, but even a newbie like me has had no trouble with it. I use it mostly to convert between MP3 and FLAC.
http://mediacoder.sourceforge.net/

2) EasyTag - Tag any audio format with this app.
http://easytag.sourceforge.net/