New Fly Fisher- Need help

Fill one medium-large box with an assorment of eggs, nymphs, and buggers/streamers, in sizes from 6-16 and you'll be set to handle nearly any fishable situation the Erie tribs will throw at you.

If I had to create a very general assortment of flies spefically for PA tribs it would be:
 
Egg patterns--#10-16 in a wide variety of colors
Generic trout nymphs--#12-16--pheasant tails, copper johns, caddis pupae, hares ears, ect.
Stonyfly nymphs--#8-14  golden or black
Streamers #4-10-- Zonkers, Bunny Leeches, Slumpbusters, ect
Buggers #8-12--variety of colors
 
 
I would suggest starting out filling your box with egg patterns, hands down they are my top producer overall.  I would then pick up just a handful of each nymphs, streamers, and buggers.  After a couple of trips you will find flies you have built confidence in, and replenish as needed.  Water conditions and time of year will dictate what flies produce well on certain days, but if you include everything above in your box you will be covered for just about anything PA has to offer.
 
Good luck and welcome to your soon to be newfound obsession.

No prob. Must haves:

Buggers: white, black, olive

Eggs:

Glo bugs in pale pink and peach
Sucker spawn in cream, pale pink, hot pink, chartreuse, and orange

There's lots more you CAN carry...but I think that those are a good base that most steelheaders would agree that you shouldnt leave home without em.

cold is 100% correct IMO.. i fish those colors all the time.. never leave home without them.. i carry any where from 4-5 boxes on me.. each 1 its only style so i never run out of flies lol.. stone flies are great producers. i only fish nymphs in "nymphy" water.. water that has a really rocky bottom for instance or fast fast near rocks.. always produces for me.. caught 11 fish on size 14 black stone flies this year.. so def DEF pick some up or tie them up.. buggers are a must.. perfect for dead drift or strip like a streamer.. i rarely use streamers but when i do i dont catch alot of fish but the fish i do are usually pigs

Some other colors buggers, I've had luck with - brown, chartreuse.
 
Good streamer to have, especially for fresh fish, emerald shiner pattern.
 
One nymph nobody's mentioned - tellico.  I'm not really sure what the heck it is supposed to imitate, but I've caught lots of steelhead with it in low slow water.  Usually fish it behind a peach or cream globug.
 
My problem, is I've got too **** many flies. Hard to pick one
sometimes.

City,
Don't limit yourself to the standard flies.  I have experianced many times that the oddball fly is the hot one when nothing else is getting a bite.

Don't get me wrong I do carry a lot of "standard" selection that is the old faithfulls but I also try to keep a small amount of the odds as well.

ok ya I was thinking about tying some but ill probably buy most of them for now, simply because of my lack of supplies and time
~also (and I dont mean to sound like an idiot, but like I said Im new) what oddball flies are used for steelhead?