There are a number of versions of NC BBQ sauce. The biggest difference between them is the use of tomato based products in the recipe. I prefer Eastern NC sauce that does NOT use tomatos (ketsup).
Here's one version.
1 cup cider vinegar
1 Tbsp sugar
1 tsp salt
1/2 tsp black pepper
1/2 tsp caynne pepper or red pepper flakes (I prefer the flakes)
Mix ingredients and let them sit for as long as possible for the flavors to blend. Make a day or two ahead is good. If you can't prepare ahead, Put in sauce pan and bring to a near boil. Turn down the heat immediately and let it simmer for a few minutes. Then, let it cool.
For more recipes check out http://www.bbq-porch.com/recipes/
Hope this helps.