There are 11 guide books to the AT, and each comes with a couple maps. I carried the map we needed and the guide book on our backpacking trip last weekend. A lot of people say the book is too heavy, and while it is extra weight to carry around, it is well worth it in my opinion. Besides useful information like how far off the main trail each shelter is, or how far water is from a given shelter, there is a lot of historical information as well. And I enjoy reading that kind of stuff while on the trail.
This book just shows the miles between significant features. I did not carry it on the trail, though, since I had the other, more detailed book.