[Highland Park] Beach/waterfront rentals Summer 2010 - suggestions

Dear Neighbors, We are hoping to get our family to the beach or to a lake this summer. Being a transplant from Massachusetts, I'm not all that familiar with where people to for that from Pittsburgh. I've heard Delaware and Rehoboth are nice. I'm also interested in lakes for a salt-free experience. I would rather not drive all the way to the Outer Banks. If anyone has had a good experience with children and a dog, I'd appreciate suggestions and specific names of rental companies or even specific properties. The only time we can't go involves the last two weeks of July. I thought of Kelly's Island in Lake Erie but was told it was boring. Thank you, Joan S. Farragut St.