Everything important should be backed up AT LEAST once, probably twice (or more).
A CD wont hold many pictures but DVDs probably will.
So I would copy your pictures to a set of DVDs, AND buy an external hard drive and copy the pictures there as well.
External hard drives are "plug and go". You plug it in and Windows allocates a drive letter to it (G or H or whatever).
You then just copy the pictures from your computer to the external hard drive.