Posted 08 October 2011 - 01:03 PM
Install Brasero if you don't already have it. Once installed it will be under Other in the menu (under Linux Mint, anyway) and/or under Sound & Video..
Run it. Choose to make a data disk and add files. Then burn it.
Next time make a separate /home directory instead of putting everything on one partition. Then when you want to upgrade or reinstall, just set it as /home again at installtion time and don't format it. Everything will still be there after you're finished.