Lost finder

My Finder has stopped working, my desktop icons have all vanished and the only apps I can open are the ones I've got showing in the dock. This happened pretty much all of a sudden, but preceded by the iBook beginning to make alarming grinding sounds.
Any advice/help/opinions greatly appreciated! Thanks, Chris G.

It's a problem with one of your drives. If finder can't properly access any drive, it locks up or fails completely. Is there a CD stuck in there? If not, you may have a bad hard drive. Take it back where you bought it asap.