Here are some links you might find helpful. Just Click on the URL to go to the website.
Potomac River Angler's Club (PRAC) Message Board - This board it mostly locals fishing the lower Potomac and Chesapeake Bay. Very helpful fishing information is available here.http://prac.proboards.com
Potomac River Fisheries Commission - Great site with all of the recreational and commercial fishing regulations pertaining to the Tidal Potomac.http://www.prfc.state.va.us/