Yes, you can ... here is how ...
iTunes is an application that allows you to encode CD tracks or audio files in .aif or .wav format into .mp3 files (as well as other compressed audio file formats).
Depending on the MP3 settings you choose, the finished files will have varying sizes. Before converting your CD Tracks or audio files, check the instructions below for changing the iTunes MP3 import settings to select settings that optimize the mp3 file size.
Changing MP3 Import Settings
http://www.wellesley.edu/Computing/Idocs/Itunes/convertMP3.html#settings
Converting CD Tracks
http://www.wellesley.edu/Computing/Idocs/Itunes/convertMP3.html#convertTracks
Converting Audio Files
http://www.wellesley.edu/Computing/Idocs/Itunes/convertMP3.html#convertFiles
If you don't have iTunes, you can still do it with one of these free programs ...
http://www.eusing.com/CDRipper/CDRipper.htm
http://www.mp3-converter.com/mp3_converter_freeware.htm
http://www.cd-to-mp3.com/
http://www.freerip.com/