you might be able to bring some samples to your local co-op extension office.
This should be all the info you need for your area:
You're lucky. It looks like soil tests are free there in NC.
Fred, not sure where you are in NC but if you get an opportunity to visit the NC State Arboretum in Raliegh, lots of great ideas for plants, trees, shrubs, perennials, annuals, bulbs. A beautiful garden too.