I import all my CDs at MP3 320kbps 16-bit audio 44khz. I do this because MP3 is the most compatible format cross-platform, you can share with anybody, and you can burn direct to MP3 CDs to play in a CD player or car stereo that supports MP3 CD format. I think the 320kbps compressed MP3s sound fine, for a 5 minute song you are looking at about a 16MB file.