I assume you're on about putting images onto the CD itself ??
If so, you can buy paper that has 2 cut-outs that you print your image on. You then peel the image off and stick it on to the CD.
A much easier way would be to buy printable CD's. You need a printer that can print onto CD's, but it's really easy to do.
Yea I wasn't too sure as well OG ..... any paper would do if that's the case, but I'd personally use something a little thicker than normal paper, 'cos when I've printed something in the past, that uses a lot of ink (an image with quite a bit of art work in it for example), a normal sheet of paper isn't quite up to the job, so use something slightly thicker.