One other issue - I was importing some Nirvana songs, and the song and album titles were not coming up correctly as they were being imported. It would say "Track 01" instead of "Smells Like Teen Spirit." Nirvana is pretty common, and even though their albums are from the early 90's, I would expect iTunes to recognize the songs.
Make sure you're using iTunes 4. Anything before that doesn't support AAC files. Once you have iTunes 4, go into the preferences, under the Importing button and choose AAC. As for the track names, it's not iTunes that recognizes it or not, it's the CDDB, a database which is accessed over the internet, meaning that your computer must be connected to the internet for it to pull up track titles and such. Good luck.
Thanks for the help - Do new Powerbooks come with iTunes 4, or do I have to download or purchase it?
I won't have internet access on my Mac for at least a few days because it won't work through the cable modem installed on our PC, and it wasn't dialing up properly (we have a 2nd phone line that we rarely use, but I get an error message saying "Server could not be found" when I try to load Internet Explorer by dialing up).