AMC's Best Backpacking in the Mid-Atlantic: I keep a signed copy on my night stand (wish I was kidding).
CNY Hiking: Awesome for identifying hikes in New York (specifically Catskills and Adirondacks); also includes a
comprehensive, state-by-state guide to the Appalachian Trail (note: mile markers along the AT included in the site are
not accurate, but may be used for approximations)
HikingUpward: Perfect for finding hikes of varying lengths in the Mid-Atlantic (PA, WV, VA, MD, NC); gives detailed
trail information including maps, mile markers, and GPS coordinates for parking
There are phenomenal sources for backpacking, adventuring, and training information that I often revisit for more information or reference. Included below are some of those sites and resources. Disclaimer: I cannot verify the accuracy of these sites or that they are current. I will note discrepancies I have found, but use your discretion.