That is awesome. Now if it would not only let you rip/record audio, but would also act like an old school data tape drive and let you put files and such on it, then I'd buy one right now.
Back on topic, the only good way is to use an audio editing program to record the entire tape from the line input. Then remove the tape hiss using noise filters in the editing program and such. Cut it apart into the various songs if you want to, and save it off as WAV files. Then encode to MP3 using LAME (www.rarewares.org
It's not really a process you can do in bulk.