This is the BEST nature guide I have found for the southeast, but unfortunately that is not saying much. I have been spoiled by the wealth of naturalist and natural history books available for all different parts of the west, books which not only tell you how to ID a species, but which also give you enough information to feel like you know it afterwards.
I take young people on wilderness trips for a living, and enjoy sharing with them my love of nature. I especially enjoy introducing them to members of the natural community, neighbors they have had all their lives but probably have never taken time to become aquainted with. I grew up in the southeast, before heading west in search of adventure. Now I am back, working with at-risk and adjudicated youth, taking them on canoe paddles in old cypress swamps and along inter-coastal waterways. I normally find a variety of great books to take on trips for my kids to consult when they spot something new. But here in my old stomping grounds, this is the best I could come up with.
The National Audubon guides are great for covering a wide range of information, from weather to constellations to identifying plants and animals. But they won't tell you much of anything about those plants and animals. I know there are naturalists and writers in the south who can do better. Would love to find them (in print) someday soon.