You should check Folly Beach – 10 minutes from downtown Charleston. Its a really laid back beachy area and you can rent beach houses in the off season for $1,000 a month or less. There are a few cute stores, cafes and restaraunts. Its a perfect atmosphere for just relaxing and hanging out.

In my personal opinion, Isle of Palms or Sullivan’s Island are better than Folly Beach unless you are a teenager, a drinker, or a surfer (which isn’t always the case when bringing a big family):

http://charlestonscvacation.reachlocal.com/

Here is a good link for rental companies. There is a link for Wild Dunes on this page, it is a great little gated community with beach access, pools, activities, etc.
http://www.sciway.net/tourism/charleston-sc-vacation-rentals.html

GOOD LUCK.

Last year I stayed in a condo on the Isle of Palms, a few minuites drive from downtown Charleston. Ours was called the Wild Dunes Resort. Here is a link:

http://www.destinationhotels.com/properties.php?id=30

We enjoyed it very much, it was a nice place to stay.

Hope you have a wonderful time wherever you choose to stay.

Isle of Palms and Mt. Pleasant seem to be rather pricey but they are so peaceful and beautiful. I’ve been to Isle of Palms twice and I’ve always been sad to leave it.

Definitely Isle of Palms for a family unless they are those wacky relatives that like seeing drunk teenagers. Wild Dunes is the more expensive part of Isle of Palms. There are lots of houses to rent out there. You might save money if you want by getting a house that faces the waterway (West) instead of the beach. It is very peaceful there and the whole place is only a couple miles wide.

Folly Beach is nice. Try Wild Dunes or Isle of Palms. James Island is an easy mid-ground. It all depends on which atmosphere you like (beach town or quiet island retreat).