There are also CD-RW discs that you can write on and erase just like regular disks. The discs are more than twice as expensive as CD-R discs, so you might not want to spend the bucks. You can only write on CD-R disks once, but that's really an advantage. You'll never overwrite your original file after making changes to it. Most digital cameras come with software that lets you download your images to a computer.
Lets take a look at the two software packages that are most widely used by digital photographers.
Once you have a lot of images, the problem becomes one of locating the one you want. This is the role of an image management program. There's an entire section on this site devoted to this topic , but you can't go wrong trying out ThumbsPlus. ThumbsPlus is a shareware program that has found very wide acceptance. There's even a Mac version in beta.