There are two generally distinct areas of thought when it comes to picking flies for Appalachian streams.
In the smaller mountain streams with mostly wild fish, fly selection is of less importance than stealth.
The larger rivers and tail waters however, are a different animal altogether and can be supremely selective.
Listed below are links to sites that discuss fly patterns of all different types for a variety of Appalachian
fly fishing situations.
For a more thorough discussion of Entomology, see
www.troutnut.com.
One of the best fly pattern archives in the south east is located at:
Blue Ridge Fly Fishing Forums Fly Pattern Archive.
Another compiled list of fly patterns that I reference often is located at:
Total Fly Fishing.com Pattern Index
For general fly tying info this forum offers a wealth of info:
The Fly Tying Forum
Also see the blog section for other general fly tying / pattern suggestions:
Fly Fishing Blogs