Don't know about Cookeville, but I know there's a good group in Cleveland Tn that runs tournaments fairly frequently (
www.dicehead.com). I'm in Atlanta, and we cruise up to Cleveland pretty often for tournaments. It's a good store they've got up there. If you're up for a trip to Atl, we run a few pretty big tournaments down here, including The Exterminatus (
www.theexterminatus.com) next weekend and a Toys for Tots charity tournament Nov 8th (
www.warfan.net/tft.html). I've also been to one pretty big tournament in Murfreesboro that I think is an annual thing, run by the people at (
www.grandadventurescomics.com). It's worth the drive too.
So, I can't really help you with local games in Cookeville, but if you're the type to travel a bit for tournaments, there are a good many that aren't too terribly far.