There are several different ways to print DVD and CD labels.
One popular and easy way is where you purchase a package that contains a plastic 'stomper' to easily and accurately affix the label to the disk, an instruction and software CD, and some labels.
These labels can be temporarily stuck on a template printed with the software on an A4 sheet so the label is in the right position for printing when it goes through your printer. The software also contains a small program for typing in a circle on the label and most even allow you to place a photo with overwriting on it.
Hope this helps.