Plantman,
I'm a pod newbie as well, I'm learning to support my daughters tune needs. Ipods support differ song formats, AAS or whatever they consider as apple standard format. They (ipods) can support MP3 format with setup parameters, or other formats as well.
Make sure you have the current download of itunes program from
www.itunes.com (the apple site). With Itunes you can download and I believe convert other song formats. You can also load in your CD's into the ipod library.
There are some tricks to get multiple ipods to share the same library as well. I think there are some online forums at
www.itunes.com, but not as helpful as here 8).
Chuck