Hi there - As a soon-to-be-former DC resident, welcome to the city. Like any metropolitan area, to make recommendations, it helps to know what you're looking for instead of doling out generic advice. You might consider checking out metroweekly.com which has a good review of bars, and regular articles about the DC scene. Some other tips, there's a gay professionals group on Meetup.com which used to be active (I haven't gone in awhile), and a group called anywhere goes - anywheregoes.com - that does outdoorsy/sporty get togethers.
Good luck in DC! Let us know if you need more targeted suggestions.
-John