I have just started to fly fish in SE Pa and I was wondering if anyone had some recommendations for essential flies that will get me through the season.
Adams! In sizes 12 to 22. Adams dry flies are great because they can imitate a lot of different bugs. Go with the standard dun to begin with, then maybe try the parachute version. The Adams is the only fly I fished for the first 3 or 4 months of learning to fish, and I caught plenty of panfish and small (dumb) trout. Enough to get me through learning the basics of casting, reading water, and getting a good drift.
You could do pretty well with adams for the darker mayflies, and sulphers for the lighter ones. Ditto with caddis flys - some in gray, and some in tan. Throw in some rusty spinners and terrestrials, and you'd have a basic dry fly selection that would suffice in many situations IMO
Volksnurse's recommendation about Zebra midges is good advice. Tie one with about 1 1/2-2 ft of tippet behind a caddis or other good floating fly (I tie the tippet to the bend of the hook of the floater). Zebra's work in sizes 16-22. You can use the same diameter tippet as you have for the floater, but I always go down on size. If using 4x tippet, I'll use 5x for the dropper tippet.
good fishing
Coughlin