A great site where you can alot of flies at the best prices Ive ever seen on the net is www.shadowlake.tk i just got a 2 dozen order of nymphs and I only payed like $12. They tell what each fly is used for too so that would probably help you as a begainer. There's lots of good places online to find gear much cheaper than in the stores, have a look around.

Tight Lines!