Go with .wav files all the way, 44,100 khz at 16 bits, which is the CD standard. MP3's will be converted to that anyway when burning your CD(s).
Addenda: the CD standard is 74 minutes, at 650 mb's a disc, which averages out to about 8.78 meg's of file size for each minute. I'd personally make some safeties after getting them on the hard drive and before any sort of editing, so go out and grab some extra CD-R's or RW's.