Re: Going to Isle of Palms next month..
Seems like the only people that recommend Hyman's live somewhere other than Charleston. To me it's a classic tourist trap, but apparently a lot of people like it.
If you're looking for "family" places to eat, Page's Okra Grill in Mt Pleasant is pretty good, but be warned it can get crowded. Might be tough to get tables for a big group together.
The Wreck on Shem Creek is dumpy and difficult to find, and the seafood is simply served on paper plates. It's overpriced a bit now compared to what it used to be before it was "discovered" by everyone, but it's hard to beat the view of Shem Creek while you're drinking a beer waiting on a table. They do serve boiled peanuts on the tables, so if someone in your family has a peanut allergy (like my daughter), stay away.
Likewise, Bowen's Island out towards Folly is equally (or more) dumpy than the Wreck, serves seafood on paper plates, but has a great water view. Personally, I like Bowens more than the Wreck, but both are good.
You can't go wrong at a beachouse buying some shrimp at Shem Creek and making Frogmore stew or just boiled shrimp.
If you get a chance park by the Ravenel Bridge and walk the bridge over the river, the view is great. Walk the Battery, and my favorite walk is the upper end of Folly by the Lighthouse. Great place for pictures.