Be warned: Optical storage just isn't a long-term back-up medium.
Recordable CDs—the kind you can burn or rewrite—tend to have more complicated degradation issues than their professionally-recorded counterparts. That's partly because they're made from organic dyes that break down faster, France told me. And as far as different kinds of discs go, CDs tend to be more stable than DVDs, mostly just because DVDs hold more data, so there's more to lose.
I used to back up to CD/DVD, until I tried to access some of those files. All gone.