To encode a cd in mp3 under ubuntu, I use wonderful Sound Juicer app.
- install sound juicer: sudo apt-get install soud-juicer
- install mp3 codec for encoding: sudo apt-get install gstreamer0.10-plugins-ugly-multiverse
- (re)start sound-juicer (applications/sound & video/music extraction)
- click on /edit/preferences/edit profiles => select “CD Quality, mp3″ then “close”
- select mp3 format in drop down list
- click on “close”
- insert your music cd and start ripping it!