It's not clear whether you have iTunes on your old computer, and intend to make CDs from there to move them to the new computer, or if the iTunes are now only on CDs ?????
If the files are on the old computer and simply need to be moved to the new computer, there are several methods that can be used.
1. A cable (wire) connection can be made between the two computers. With Vista, and I believe with most Macs, a suitable transfer program is present. The program is required on one or the other of the two computers, but not generally on both of them. The cable used for the connection usually is a special kind, in ancient times called a "zero-modem" serial cable. Help files on your computer should give details.
The main difficulty here is that the two computers must be located close enough to each other to stretch the cable between them.
2. You can, as you may have suggested, use the old computer to make CDs containing the files that you can use to copy the files to the new computer.
3. You can use any of several other "portable media" kinds, like thumb drives or external hard drives to copy the files to the drive, and then just connect the drive to the new computer to copy them to the new hard drive. Both of these probably will connect to a USB port on either computer, although firewire versions are available. The "extra" drive will look like "another hard drive" while connected.
4. You could find a "website storage" location and copy them to the website, then copy them from the website to the new machine. You probably should not consider this method unless you have a moderately fast internet connection for both machines.
5. You could (not really recommended) attach the files to emails addressed to yourself, send them from the old machine, and then receive them on the new machine and save the attachments. (A thumb drive would likely be quicker.)
A CD can hold about 700 MB of data. Calculate the number of CDs you'd need if you have quite a few files.
A 1 or 2 GB "thumb drive" will run about $20 (US) and they're widely available. Again, you may want to figure how many separate copy - move - copy - delete cycles would be required. Thumb drives up to about 8 GB are easily available, but prices run to $100 or more (in my local area) for the larger ones.
A portable external USB hard drive would give you an extra drive for backups after you finish the transfers. You should be able to find a 100 GB for under $100 (US) or something around 250 GB for a couple of hundred. "External backup drives" could also be used, but my experience with external "desktop" hard drives has not found them particularly reliable if moved around even a little.
There are several other possibilities, but these are perhaps the simplest.