I lived in Va Beach for two years, beautiful but crowded (at least in the summer). We spent time at Busch Gardens (which is actually about an hour drive north), and Colonial Williamsburg (about 45 minutes north). Things right in the city are Mt. Trashmore and First Landing State Park if you like outdoor recreation. Also, the actual "Virginia Beach" is nice depending on when you go. You can go over to Norfolk Naval Station and see if you can get a tour on one of the submarines or an aircraft carrier. Right across the bridge into Hampton (boo Hampton University) are lots of things to see about the Civil War. At teh corner of Independence Blvd and Virginia Beach Blvd are a lot of chain (but nice) restaurants, Cheesecake Factory, etc.
Hope you enjoy your trip. I'm military and was staioned at the amphibious base in Virginia Beach for 2 years, I bought a home there but am trying to talk my wife into moving to Iowa when I leave the Navy...no luck yet.