Hi TJ
there is a dojo search feature here on Aikiweb, also you can look here:
http://www.aiki.com/directory/dda-h.htm
it may be a couple years old but shouldn't be too out of date. Also I know there are some forum members in the Maryland/DC area, they'll probably be able to give you some help.
Sure wish I had started when I was 14!
enjoy training