If the back of the game is blue than you use a cd-r. If the back of the game is gold or silver than you use a dvd-r. If you have a cd-r burner, check
here to see if its CloneCd compatible. If so, use CloneCd to back up your cd based games. For dvd based games use PrimoDvd. You can download PrimoDvd and read the CloneCd and PrimoDvd tutorials
here