I won't repeat most of the previous responses, but here's my take:
--The hike from the dam up to Vandeventer is a nice, steep climb. Vandeventer Shelter is right on the trail, don't take the blue blaze trail just before it--that goes down to the left and to the water source--it is extremely steep, and around 1/3 mile. You cant see the shelter from that blue blaze, and I originally thought the blue blaze led to the shelter. Most people who went down there recommended against it. So don't plan on using that water source unless desperate. Vandeventer has a rock outcrop behind it with outstanding views. Great place to grab a seat and a snack.
--Just take a spare set of batteries for your headlamp, should have no issues getting to Damascus.
--I recommend Black Bear Resort--about .5 miles road walk to the right, when you hit the pavement at Dennis Cove Rd.
--not exactly sure when, but about 30 miles before Damascus the trail gets much more reasonable/easier. I did a 16 mile day when I normally could do about 12mi/day. I did more miles/day through that stretch than anywhere else on the AT (Springer to Marion, VA).
--Ditto on the Sawyer Squeeze
--go down to Laurel Falls--beautiful spot, and the trail goes right beside the river against a rock wall. Neat area.