First your clubs should be able to point you to swap meets in your area. Ask them if they don't know then drop 'em.
Second google Ham Nation. it is an on-line "TV" show and they too talk about some of the MAJOR hamfests. For example Dayton Ohio in may and Huntsville. Right about now (not sure if past or future in fact it's that 'Right about')
Next All the ham radio stores. DX Engineering, Giga parts. HRO or is it Amateur Radio Outlet. Even some you've never heard of like the one near my insurance agent. (
http://www.adamselectronics.net/home.htmlall have "used" though you may have to e=mail 'em to find the listings.
QST has a "Classified" section. though it's been a while since I reviewed it and you can sometimes fine dealers there.
I do not have a lot of info on Tn. but I do know there are a couple of swap meets around Atlanta GA. (I hang in Upstate SC in the wintere about an hour out of Atlanta).
Also you may find info on the ARRL web site regarding swaps and clubs in your area.