It's been 15 years since I guided on the rivers on POW, but I recall late July and early Aug mostly being pinks and chums. Fun to catch but not so fun if you want to eat them. Sockeye will be around too but tough to get to bite. Coho will be trickling in but you can't count on them. Whale Pass has an early coho run at Neck Lake that would be worth checking out though. I'd look at fishing lakes too for trout. Some very good trout fishing that pretty much flies under the radar. Early Sept is prime time for hitting lots of fish in the rivers. You'll wear yourself out as pinks are still around as well as cohos starting to really get going. Lots of self-guided anglers around though and getting lodging and a vehicle rental could be tough.
I don't think which community you are in matters. Everything is paved now and you can really get around the island. Craig/Klawock is the hub of the island and gives you good access to a wide variety of rivers as well as places to eat etc. The Klawock River has the worlds largest coho hatchery at the top of it, so it's pretty popular. You will need a $100 access pass to fish it though. A vehicle is all you need unless you want to do some saltwater fishing.
Good luck. It's a cool island with lots of places to cast a line.