Backing up your iTunes library to CD or DVD
You can easily back up your iTunes library, playlists, and iTunes Store purchases for safekeeping. To reduce the number of discs needed for a backup, iTunes can perform incremental backups (only items added or changed since the last backup).
To burn a DVD, your computer must have a SuperDrive. Some third-party DVD burners may also work. (For more information, click the first link below.)
To create backup CDs or DVDs:
Choose File > "Back Up to Disc" and then select your options.
Insert a blank disc (CD-R, CD-RW, DVD-R, or DVD-RW).
Click Back Up.
iTunes burns the number of items that fit on one disc, and then asks you to insert subsequent discs to continue burning the remaining files. Don't eject a disc while a backup is in progress.
To restore backed-up files, insert a backup disc, choose File > "Back Up to Disc," and then click Restore.
Spoken programs purchased from the Audible website are not backed up.
Discs you create using the iTunes backup feature can be used only to restore; they can't be played in a CD or DVD player.
Edit: Found this link as well.
http://docs.info.apple.com/article.html?artnum=302392