I moved to the area last year and had all of these same questions. Answered some through the generous advice of others while the rest was answered through a lot of blood, sweat, and tears of fishing the area. As far as waders go, in an ideal world, one would have two sets of waders: one made of neoprene (3mm or 5mm) for the winter time or colder glacial streams (i.e.-Sandy River)and the other made of a breathable material for the summer or warmer times of year. I found a pair of 3mm neoprenes at Cabela's (
www.cabelas.com) for $59.99 and was just looking at a pair of breathable waders that they sell for $49.99. The breathable pair doesn't look real durable but also I just need them to keep me dry in June-September. I definetely would recommend their wading boots that are sold separately for $50-$70 with felt soles a must because the rocks are very slippery. If two pair aren't economical for you, I'd recommend a pair of 3mm neoprenes that are warm enough for the winter yet thin enough for the summer too. Definetely get chest waders as you never know when you'll need the extra height to get across a stream.
As far as fishing an area, I'm a firm believer that if you know there are fish in a particular area, stay there and fish it as it may just take trying a different lure/bait. They will bite sooner or later. If you aren't sure whether fish are there or not, if you don't get a bite after a half hour of trying different lures, baits, presentations, and retrieve speeds, move on and repeat the process. In all likelihood, you will find a method that is more effective than others in a particular hole. Good luck fishing. This definetely is a great place for it.
-Dakotan