You're not that far from Lake Barkley and Kentucky lake on the Tennessee River both are very good lakes for pan fishing. This time of year find a creek arm and go to the shallow end or back end of the creek. Find the old creek channel and bottom bump a minnow close to or in the drop off into the creek. You'll find Crappie moving toward the backs of the creeks. You can also troll with your trolling motor pulling small jigs, once again follow the old creek channels and you should be able to find crappie. This time of year Bluffs for blue gills 10 to 12 ft. with small jigs or worms under a cork.
If you don't mind the drive Reelfoot Lake just off the the Mississippi river can be a bonanza for big Crappie fished the same way.
Interesting fact about Reelfoot, the lake was formed when the New Madrid fault slipped causing a really big earthquake back in 1812. The land around the Reelfoot dropped several feet causing the Mississippi River to run backwards for 3 days while it filled the lake.

The Cumberland river runs just south of Clarksville and I know there is decent fishing there also but I've never fished it so I really can't help much there but Crappie this time of year will follow the same patterns no matter what body of water you fish.