Oh you have squirrel hunters in here too. I just worked that one out last week. heres the video. I've worked it out a little and cleaned it up a bit since I posted this.
Wait, what chords could you possibly want to play besides C, G, and D?! :P
It obviously depends what tuning you are in. The most common tunings for old-time music are open G (gDGBD), which can be capoed up to A to play along with fiddle tunes, and double C (gCGCD), which can similarly be capoed up to D.
Frailing the 5-string Banjo really helped me out when I was learning clawhammer. It has awesome chord diagrams for each tuning that hint at how to move up the fretboard and screw around. You should check out Mike Iverson's web site too.