Percy Priest Lake, near Nashville, TN, is actually a reservoir created when the Stones River was dammed in 1968. There are about 14,000 surface acres of water during summer pool (the lake drops about 7 feet during winter). The lake is surrounded by 19,000 acres of public land.
One popular place to paddle is at Hamilton Creek. This is the home of the Percy Priest Yacht Club and is where Vanderbilt's rowing team practices. Very flat, protected water here with a nice floating dock as well as easy shore access. The TSRA meets here often to paddle, including every Wednesday late afternoon in the summer.
In Hermitage, Old Hickory Blvd. runs straight into the lake. There is plenty of parking and this is a popular boat ramp on weekends. The shore here is dirtier and you must be mindful of stepping on fishing lures or broken glass in the water. The water can get quite choppy here with the boat ramp and also if the wind is blowing from the southwest, unimpeded across the lake.
Also in Hermitage are Cooks and Seven Points. Both are great for kayaking. Cooks is a simple, no frills, area that opens into the heart of the lake. This can make conditions quite choppy here. Good starting point for a long paddle. Sevens Points is more protected from wind, but that makes it more popular with wakeboarders and skiers. If you head east back up Suggs Creek, it is quite calm and too shallow for speed boats. You an also access Suggs creek from Vivrett boat ramp.
Some nice paddles might include leaving from Hamilton Creek and paddling out to Bear Island or Luau Island. A personal favorite paddle is to start at Cooks and head straight out across the lake, past Bear Island, past the party cove, and continue to the Hobson Pike Bridge. If you do such a paddle be very aware of speedboats and jetskis. Also be aware of very fast bassboats leaving for tournaments in the early evenings.
There's camping and restrooms at some of the areas around Priest.
See the official site for more info: http://www.lrn.usace.army.mil/op/jpp/rec/
A few recreation areas are 'fee areas', though they usually have other spots at those areas that are free (for instance Cooks Rec. Area has a campground area and a swimming beach area that are fee based, but also has a boat ramp and other areas which are free). You can find a place to put in with no problem, for free.
No permits or registration required. PFD are required to be onboard your kayak but not worn. Racing kayaks do not require PFD on board.
The locations above are some of the easiest/quickest to access from I-40.
Hamilton Creek area - Exit I-40 on Stewarts Ferry and head south. It will change to Bell Road. Continue past Elm Hill Marina. Turn left when you see a sign for "BMX". When you enter the area, the first right will lead you to the BMX course, mountain bike trails and a cove where many boat demos are held. The Yacht club area is further up the main road at the first left. The main road ends at a standard boat ramp area.
Cooks and Seven Points - Exit at 221b Old Hickory Blvd. and head south. Left on Bell Road until end. Right on New Hope Road until end. Go left for Seven Points, right for Cooks.
If you take the same 221b exit and head south and don't turn on Bell Road, you will find yourself at another unnamed boat ramp.