The Charleston Visitor's Center is a bit more than just a place to get information. There are a few historical exhibits and displays, including a large, glass enclosed layout of the city set into the floor at the entrance. They have added interactive touch panels at each corner to help you locate some attractions in the area. The map itself is quite impressive. You can find assistance with hotel reservations and book tickets for a few select harbor tours. The walls are filled with brochures for everything ranging from restaurants, tour companies, accommodations, and other attractions. The Charleston Visitor's center offers free parking for 30 minutes.
This is your best bet to start your visit to Charleston. The lobby area is full of flyers for area attractions and restaurants. You can also buy tickets for a number of tours.
I highly recommend checking out the Visitor's Center before getting started with your exploration of the city. You'll find a variety of maps and brochures, as well pick up a copy of the Charleston CVB Visitor's Guide, which always features a number of business, attraction, lodging and food listings, as well as some first-rate photography.