Wade fishing, you're definitely going to want to go on low water.
This is a helpful archive post about how long it takes for the water to rise/fall at various access points when the generators cut on/off at Center Hill: http://www.fishingtn.com/showthread.php?t=6838
Zebra midges under a bobber are an alright place to start. Some YouTube videos on indicator nymphing will probably be more useful than anything I could type on the matter.
Size 10-12 woolly buggers fished the same way can also be effective. Additionally, you can lose the bobber with buggers and experiment with pulling them back in short strips and/or letting them swing in the current. Day in and day out, these techniques are usually not going to land as many fish, but losing the bobber makes casting a whole lot less of a chore. You'll deal with a lot less frustration from tangles, which is a very real consideration when you're learning to cast.
I think the least frustrating way early in the game to work on the cast, catch some fish, and have some fun is to throw some little popping bugs for bluegill anywhere you can find them. They'll take any ol' nymph or small streamer too.