I read the ilounge link twice, but now am confused as I will explain below.
Moved main PC with itunes down stairs (on line, working). Bought new iMac as the main computer (the computer I want itunes, ipods, phones synced to). Start reading on how to transfer library. Go upstairs and itunes found the library on the old pc.

Now what do I do? I had a back up drive hooked up to the pc and was hoping I could use that to transfer in the library which I'm (pretty sure) is on there backed up. Will I have doubles of each song in the library if I hook this hard drive up to the imac? I don't really want itunes or content on the old pc in the future as I want to use the old pc for flac files.
thanks for any assistance.