Transportation

Washington Metro Transit Authority (subway and bus info)

Metrorail System Map

Alexandria DASH buses

Arlington County ART buses

Fairfax City CUE bus

Fairfax Connector

Georgetown Connection

Montgomery County Ride On buses


 

Commuter Store sells Metro farecards and has lots of printed schedules.

DMV's:

Virginia Department of Motor Vehicles (You can check wait times at some VA DMV locations.)

Maryland DMV

DC DMV

Zipcar

can be a good alternative to owning a car. You pre-register, then you can reserve a car (you can do this on the Internet), and you pay by the hour. They have cars located all over the area at convenient locations like Metro stops, etc. They use special magic cards to let only you unlock your reserved car.
This could be a great alternative to owning two cars for a couple.
Flexcar and Zipcar also use some hybrids, if you want to try one out.