Here's a new book...
The Appalachian Trail and American Environmental Politics
by SARAH MITTLEFEHLDT
The Appalachian Trail, a thin ribbon of wilderness running through the densely populated eastern United States, offers a refuge from modern society and a place apart from human ideas and institutions. But as environmental historian and thru-hiker Sarah Mittlefehldt argues, the trail is also a conduit for community engagement and a model for public-private cooperation and environmental stewardship.
In Tangled Roots, Mittlefehldt tells the story of the trail’s creation. The project was one of the first in which the National Park Service attempted to create public wilderness space within heavily populated, privately owned lands.
Here's a good book for MST trail hikers by Walt Weber, available from Amazon
Carolina Mountain Club and its members interface with many other trail-related organizations. Here are links to their sites:
American Hiking Society
Appalachian Trail Conservancy
A.T. maintaining clubs
Blue Ridge Hiker - hiking trail guides for Dupony State Forest, Gorges State Park, and Pisgah Ranger District
Blue Ridge Parkway
Blue Ridge Parkway Foundation
Carolina Mountain Land Conservancy
Diamond Brand Outdoors
Friends of the Blue Ridge Parkway
Friends of the Mountains-to-Sea Trail
Friends of the Smokies
Hiker Resource Guide USOutdoor.com
How to Prepare for Your Backpacking Trip backcountry.com