Tremont - the Middle Prong - has great access all the way up to the horse trailer park at he top of the gravel road. Granted there are some spots where you'd have to climb down a few boulders/rocks/banks, but they're worth the effort. You could drive up to the horse trailer park, and then take either the Lynn Camp Prong trail on the left (an old graded rail bed) or the more primitive trail on the right to Thunderhead Prong. I've found the Lynn Camp Prong to be more productive than Thunderhead. And if you hike up far enough you're in true Brookie country.
Or try Elkmont. Again it's an old graded rail bed, gentle grade for the most part with easy stream access. From the entrance on up you'll find browns, bows and eventually brookies. I believe some of the bigger brown have come from the section between the entrance off LR road and the bridge. It's also a very pretty stream and consequently draws an inordinate number of tourists - especially with the campground right there.
The West Prong of the Little River definitely has more water this year. You might want to try hiking up from the confluence of LR and Laurel Creek... gorgeous country and you can find a few runs and pools to try.
If you're up for a little more drive time, you can't go wrong with the West Prong of the Little Pigeon river above the Sugarlands visitor center. You can pull off at any of the "Quiet Walkaways", hike a few minutes and be into some very nice but moderately technical water. Take 441 up to the Chimneys and you're in for a real treat. Walker Camp Prong runs right alongside the road from the Chimneys all the way to the switchback at the top. You might have to bushwhack your way into a few spots, but once there you'll find you can sight fish for both bows and Brookies. It can get a little tight, but since your casts will all be fairly short, a 9' rod shouldn't be a problem.
Both my son and I have tried all of the spots I've mentioned -- me with my 8' or my 8'6" rod and him with his 9' rod.
I think most of the beginner classes (whether LRO or independently guided) start out putting their beginners on the water at Metcalf Bottoms. Easy access for groups, relatively low and consistent water flow, and wide enough spaces for two or more bodies to stand side-by-side for instruction purposes. I have seen and caught fish there, both large and small, but not when there's a great deal of activity in the area. I know that Hugh Hartsell, for example, will use Metcalf Bottoms as an on-stream classroom when it's convenient, and then move his clients to more productive water once he's confident of their casting and mending abilities.
If you can at all, I would highly recommend an LRO class or at least a half day guided Smokies trip with Mr. Hartsell http://smokymountainflyguide.com/
to flatten the learning curve.