How can I back up my song ratings (0-5 stars) in iTunes? In what file(s) are they stored?
Options Keep iTunes Media folder organized and Copy files to iTunes Media folder when adding to library are both unchecked in my case
Song star ratings are stored in the iTunes library database file.
Usually (for Windows vista/7):
also a good idea is to backup the xml file. This is the file iTunes reads if the database get corrupted
note if you want to transfer songs/star ratings from one computer to another, change the drive your music is on, or reformat your computer; you probably want to read this article about how the .itl and .xml files work.