The most direct way to get to VA Beach from Washington D.C. is I-95 South to I-64 across the Hampton Roads Bridge-Tunnel to
I-264 - The Virginia Beach-Norfolk Expressway. However, there can be a lot of traffic on I-64, which moves slowly.
An alternate but longer route is to take I-95 south from Richmond, exit U.S. 460 at Petersburg; follow 460, which intersects with I-64 in Chesapeake; take I-64 to I-264 - The Virginia Beach-Norfolk Expressway.
The most direct route from a northeast city like New York is U.S. 13 South through Virginia's Eastern Shore and across the Chesapeake Bay Bridge Tunnel, which is an experience in itself. The Chesapeake Bay Bridge Tunnel is a four-lane, 20-mile-long toll crossing of the lower Chesapeake Bay. It was designated "One of the Seven Engineering Wonders of the Modern World." There is even a restaurant and a gift shop on one of the manmade islands that connect the bridges.
Be careful - when leaving VA Beach TAKE exit 14, which is I-64 N, to get back through the tunnel. If you miss the exit, you will find yourself heading across the bridge into Portsmith. (I have done this twice.) If you miss the exit, it is much quicker just to turn around than it is to take I-664 back to Hampton. The bridge into Portsmith is a drawbridge, and if you have impeccably poor timing as I did, you will get to experience the bridge opening to let a boat through.
If you are flying in, consider Norfolk International Airport as an alternative to the busier Richmond International Airport.
There are six major airlines that service this airport: Continental, American, Delta, Northwest, Southwest, and Independence Air.
Norfolk Airport:
http://www.norfolkairport.com/