MD CAP Freqs
The BEST source of info is on the MD Forum page. On of the regulars, TinEar makes multiple daily posts to a sticky thread for Militay air traffic in the Maryland area. If you don't pick up enough freqs by reading his posts, drop him a reply and I'm sure he will help you out.
Reaing his posts is almost better than hearing it firsthand-no waisted time w/o radio traffic!
Happy scanning
Dan