There are three sections in the web page, and they cover (1) Washington DC and a few very close in locations in Northern Virginia, (2) places to which you can make day trips from the Washington DC immediate area, and (3) links to other areas in the US (for example, city and state tourism and visitors' bureaus, National and State Park listings, etc.), air and rail travel contacts, show and sport ticket purchasing info (Ticketmaster), and a site where you can get quick weather information for travel destinations.
These lists are not meant to be exhaustive -- just enough to get you started before you leave here. Once you are there, newspapers, "yellow pages", and local contacts can fill in the gaps.
Get the Internet links at: http://www.mmdtkw.org/WashDCEnvirons.html