Welcome to the area. I am relatively new to the area too. I moved to the area last August, but live further west in Loudoun County. I am sure that I am too slow for you anyway but there are many tri clubs in the area. I joined up with the DC Tri CLub but most of their training events are in DC or closer to Arlington/Rosslyn area. I have also heard about a tri club in Reston that may not be too far.
I would be interested in meeting up with a few people for a group ride on the WO&D trail. I get on at Rt. 28 do an out an back to Purceville (about 41 miles). I ride by myself but find if I hookup with some other riders I push myself harder.
Did any of you end up meeting in the NoVA area for any Swim Bike Run's? I live right off of the W&OD trail in Sterling and would be willing to meet up as well. Where are you all getting your swims in?