You could connect them with either an ethernet cable, or get a flash drive to copy the files across, or an external hard drive, or burn the stuff to a CD or DVD...
You want to copy the folder documents and settings\[username]\my documents\my music\itunes.
Then copy it to the same place on your other computer. If the usernames are different then you may have issues and may have to add your music into iTunes again on the computer you're copying to.