My mother has lived on Oak Island (Holden Beach is on the eastern end of the island) for the last decade.
The beach itself is just a beach -- a lot of condos and a pier. There is golf course, although it's nothing to shout about.
You're not too far from Southport, a lovely little community on the water with some great restaurants. You can also catch a ferry there that runs across the Cape Fear to the tip of the mainland near Fort Fisher and the NC Aquarium -- both fascinating places to visit -- although your young ones might be a bit too young to appreciate them.
Other than that, you're almost an hour away from Wilmington, the battleship (again, when your kids get a little older) and the more built-up Wrightsville and Carolina beach areas ... although I have to say that Holden and the rest of Oak Island are getting fairly built up too.