Using Garageband - Cassette to MP3

here's the short version:

http://www.bulletsandbones.com/GB/GBFAQ.html#recordcassette

(Let the page FULLY load. The link to your answer is at the top of your screen)

and a longer, hand holding, tute for transferring LP records (the goal being the same):

http://www.bulletsandbones.com/GB/Tutorials.html#allabouttransferringlps

One thing I would add to HT's excellent tute is the use of the Cycle Region. Instead of cutting and moving sections of the recording to separate tracks for exporting individual songs, you can use the Cycle Region to export the portions one at a time.