Success in this game depends as much on the antenna as it does the scanner. That little duckie isn't going to be very efficient in the UHF milair area (too many obstructions, ect.). You really need to get a better outdoor antenna (scantenna, discone, something from DPD productions, ect.) if you want to get into this game.
Depending on precisely where you are, you might have a chance at the approach/departure freqs, along with the SFRA (Special Flight Rules Area) stuff found in the Potomac TRACON (Potomac Consolidated Terminal Radar Approach Control) which you should already have in your library (Anne Arundel County / Baltimore Washington International Airport). I don't have an 800, but the database has them, so you should. You should know that not all of these freqs are always up - when I lived in Glen Burnie, there were certain days where some freqs were up, others not. They are often patched with their Civil Air counterparts to keep the civilian pilots aware of where the mil flights were
I would also strongly suggest 360.7, which is the UHF side of the 134.5 SWANN sector, which is very busy. I even hear them on occasion here in the Bowie area. That's a pretty good test frequency - the further out you hear, the better your system is working
I'm sure others have some more suggestions, but the key here is a better antenna, if you don't have one already...Mike