You would save yourself a ton of time by not burning a bunch of CDs for backup. You should instead buy an external firewire enclosure, an IDE drive off ebay (120 GB for $45-60), a firewire card for your PC (super cheap off ebay), and simply use the firewire drive (formatted to FAT32) to copy all your data to. When you put it all on the mac, wipe the whole drive, reformat it to a Mac-only format (assuming you don't want to use it with the PC ever again), make a complete dupe of your internal HD using SuperDuper, and voila you have a backup of all your data as well as a bootable copy of your hard drive.
Then make DVD data discs of your music, movie, and picture files and store them off-site (a relative's house, etc.). That way you will still have them if your house burned down or something. A CD only holds about 650 mb, while a single layer DVD holds 4.7 GB, therefore for every DVD you burn, it would take seven CDs for the same amount of storage.