Mushrooms of the Southeast by Todd F. Elliott & Steven L. Stephenson
Highly recommended by Fungi Jon for Florida and Southeastern US states as a regional reference book, especially for beginners. It's a light-weight, concise book, perfect for bringing in your backpack or basket while hiking and identifying mushrooms.
If you're into mycology and live in the Southeast, I wouldn't go without this one in my collection!
"Mushrooms of the Southeast is a compact, beautifully illustrated guide packed with descriptions and photographs of more than 400 of the region’s most important mushrooms. The geographic range covered by the book includes northern Florida, Georgia, South Carolina, North Carolina, Virginia, Delaware, Maryland, West Virginia, Kentucky, Tennessee, Arkansas, Louisiana, Mississippi, and Alabama. In addition to profiles on individual species, the book also includes a general discussion and definition of fungi, information on where to find mushrooms and collection guidelines, an overview of fungus ecology, and information on mushroom poisoning and how to avoid it."