There are a few ways:
1) You can buy one of the many cleaning kits.
2) if someone you know wears glasses, get a lens cloth from them.
3) buy some lens paper (it\'s dirt cheap) and use a bit of warm water.
Note: Don\'t use linty kleenex.
Note: Always clean from the center out to the edge, never go in circles around the CD.
Note: Those "resurfacers" work pretty well, but the liquid is expensive, and if you screw it up... well.....