[iTunes] iTunes 7 question

[Ron Michael]

I just got a new MacPro and need to copy my iTunes files from my old  
G4. What files do I need to copy and where are they located? I copied  
a .xml file and that took care of what appears to be most of the  
files. But I'm missing some of my playlists that were on my iPod. Do  
you know where they are? Are they stored on the iPod itself instead  
of the computer? Is there a utility program available that might take  
care of the whole job?
Thanks a lot for any advice.
Ron in Memphis