Rangers will answer your questions if they can. You can learn a great deal about the park from campfire programs and conducted walks, and from the exhibits in the two visitor centers.
For more detailed information on a specific subject, you'll need a book. The Shenandoah National Park Association (formerly the Shenandoah Natural History Association) is a non-profit organization. It sells books at Dickey Ridge Visitor Center (mile 4.6), and at Byrd Visitor Center (mile 51.0). The profits are used to publish other books and to support the many interpretative and educational activities of Shenandoah National Park. You can also order additional books and many other publications online. Many of the books have already been mentioned, but here is a listing of particularly recommended books:
In the Light of the Mountain Moon: An Illustrated History of Skyland, by Reed Engle. The history of Stony Man Resort which became a part of Shenandoah National Park. 135 pages with black and while photographs.
In the Shadow of Ragged Mountain: Historical Archeology of Nicholson, Corbin, & Weakley Hollows, by Audrey Horning. The story about the families who lived in these hollows prior to the park. 115 pages with black-and-white photographs and illustrations.
The Greatest Single Feature - A Sky-line Drive: 75 Years of a Mountaintop Motorway, by Reed Engle. The history of the building of Skyline Drive. Black-and-white historic photos.
Shenandoah, the Story Behind the Scenery, by Hugh Crandall and Reed Engle. Photographs by William Bake, Jr. 48 pages. Covers about the same range of subjects dealt with in this book up to now, but more concisely. The color photographs are beautiful.
Herbert Hoover's Hideaway, by Darwin Lambert. 143 pages. This is the story of President Hoover's summer retreat at the head of the Rapidan River. Now known by its original name, Rapidan Camp and part of the park since its establishment. Black-and-white photographs.
Undying Past of Shenandoah National Park, by Darwin Lambert. 330 pages. The most complete history of the park.
Shenandoah Secrets, by Carolyn and Jack Reeder. 184 pages. More historical data about the areas that are now within the park's boundaries.
Everything Was Wonderful: A Pictorial History of the Civilian Conservation Corps in Shenandoah National Park, by Reed Engle. A history of the six CCC Camps in Shenandoah National Park. 112 pages with 104 black and white photographs.