cmc934makes a good point. Depending on where you live "by Memphis" that might be closer.
Back to Normandy. An important point about fishing tailwaters is to know the water release schedule and what release amount is fit for fishing for the dam you want to fish. See
http://www.tva.gov/Environment/Lake-Levels. With the recent rains lots of water is being released which hampers tailwater fishing. Today Normandy is releasing 1500+ cfs (cubic feet per second). It's possible to bank fish at around 700, but 400 is just about an upper limit for fishing/wading. Ideal is 200 and less.
Look at a map of the Normandy area. Notice that there is a bridge right below the dam (I can't remember the name of the road). Now look at the river. From the dam the river makes about a three(?) mile loop and crosses the road again very close to the village of Normandy. There is also a bridge there.
If you are wading you can start at either bridge and have plenty of river to wade. If you are using a canoe, kayak, or small boat you can float the entire loop. There are access points and parking at both bridges. If you have two vehicles then you can float bridge-to-bridge. If you are using only one vehicle you can start at the lower bridge, go upstream, and float back. I use a canoe or small jon boat with a trolling motor and do that.
Any of the trout fishing methods that you are familiar with will work. I use light spinning gear and mostly Gulp Power Eggs (yellow or chartreuse) and drift fish. Trout magnets, Panther Martin, Kastmaster, Jake's Spinner, most any small shiny spinner, worms, and corn all work. I don't fly fish so I don't know any of those fancy-named bug looking things to recommend.
You will catch mostly rainbows. I'm not sure if they stock browns in the Duck, but they do on the Elk (Tims Ford). Size will range from 7-8 inches with plenty ranging 10-12 inches. 14-inch fish are not uncommon. I have caught 19-20 inch brood fish that have been removed from the hatchery but that is not common.
Something to understand about the Duck river is that the water tends to be warm, too warm for the trout to carry over year-to-year. On the Elk River the water stays cold enough for trout to carry over and thus the size of the fish there can run a little bigger. On the Duck River, because of the warm water, stocking is done from November-June. After June the water is just too warm for the trout. On the Elk River stocking is done March-November. I live close enough to both that I fish the Duck in winter and spring and then shift to the Elk. That provides me with trout fishing year-round.
Obviously I like to talk about fishing (and a few other things).
Hope I have given enough info to help.