The Southern Living gardening book gives lots of good info on plants that grow well in the south, and it divides the south into several regions based on climate(Upper, Middle, Coastal, Tropical, Lower). I would start there and pick out the plants you like/think are pretty to anchor the various spots you'll have with plantings (as long as they'll adapt in SC, that is).

**Apparently there are a few other Southern Living books that will complement the main book (see link, and look at the landscape book, and the problem-solver book! They look great to me!) For a cheaper option, go to the library and/or Half Price books to see if they have any copies.

In terms of overall gardening plan, be sure to pick-out plants that will grow/bloom at various times/seasons so that you'll always have something pretty to look at.

I was reading a gardening book a while ago (from our local library) that was pretty good for setting-up a new garden. I can't remember the name (I'll try to look it up), but it talked about determining the "purposes" of various areas, like play, eat/entertain, relax, food (herbs/vegetables). Sketch a general drawing of your yard and determine which areas you want to designate for these purposes.

The web and library are awesome resources (besides this site). For now, go to google and type something like "plants for sandy soil" and you'll probably come up with several good links.

Also (and finally), as you are doing, you can always amend your soil so that it's not all sand. Most plants prefer a well-drained site so you're starting off well. To improve it, definitely add manure as you are doing, also wood chips/bark and possibly topsoil. The blend of sand and all of the above will be great soil.

Here is a link that might be useful: Southern Living books

I saw this book online, too.

Here is a link that might be useful: Planning Your Garden