need help retrieving iTunes files and iPOD !!

I had a 4yo iMAC G5 which just died. I just bought a new 27" iMAC a few days ago.
It's a blank slate. Two problems:

1. I saved the harddrive from the old MAC and want to retrieve all my old iTunes files from it into my new MAC. I have hundreds of $$ invested in iTunes downloads.
I have no idea how to do this. I know it won't be as simple as copying files over. Can I do this myself or do I need help from Apple????


2. Now, my iPOD does not talk to the new MAC. When I connect up to iTunes, it says that my iPOD is registered to a different MAC (my old one) and won't let me do anything.

I'm a MAC noob so I need some help.

Thx,
Rob