These are the kits I've been using. I bougfht the mandrel for them as well. All you have to do is drill the blank, tap it with a 3/8-16 tap, screw the mandrel on, chuck it up and turn.
They are really easy to do, and make great gifts. And, from what I've seen, they go pretty well at craft fairs, too.
Do you glue up your own blanks to get the multi color stopper like in the picture?