I don't know about anything for NC specifically but here are a few suggestions.
Snakes of North America, Eastern and Central Region, by Tennant is one of the best snake books. (As a bonus, it also has a awesome paining of an Okeetee on the front by my friend Ed Acuna.)
Good general guides are the Peterson's and the Audubon Field Guides. They aren't as specific but cover most of the more common species top include amphibians, and lizards.
You might see if Rich has these in his FaunaBooks section.