You're going to have a great time there. We spent three days there two years ago.
You can't go wrong up and down King Street. Burns Alley, King Street Grill, Sermet's Downtown (which has a jazz bar upstairs).
On Meeting Street, there's a really cool place called O'Hara & Flynn where you can just sit, taste wines and eat cheese.
Get down to Market Street, where the Charleston City Market is -- and you won't want to miss that, either -- and there's a unique bar called Henry's House. Three levels, and each one is a different feel.
For food, the area around the market is fabulous. There is a hole-in-the-wall Italian place, like maybe 15 tables, on the right side of the Market toward the water.It was one of the best meals I've had in years. I just can't remember the name. If you are a crab fan, the Charleston Crab House is down there.