You rarely go wrong with the Peterson Field Guides. Amphibians seem especially threatened by climate change. We need to know and protect them. Another good book, by Donald W. Linzey and Michael J. Clifford, is Snakes of Virginia.
This news of being named an [ALA] Alex Award winner is especially sweet because I, personally, know what it means to be included into a world of free access to books, which has been my real family since the first day of the first grade, when I stepped into the bookmobile.