This is a fairly simple trip. Metro also has help available at all stations, so you ll find your way easily.Take bus 5A heading towards L Enfant Plaza. Exit at Rosslyn Metro Station.From Rosslyn Metro, take a Blue Line train heading towards Largo Town Center. Exit at Metro Center.From Metro Center, take a Red Line train heading towards Glenmont. Exit at Brookland Metro Station.Total travel time should be about 90 minutes.
I was at Dulles and went in to DC from the airport. Took the Washington Flyer bus - that takes you to a Metro station and you can pretty easily navigate the Metro from there to get to the station you need. I think it was $13.00 one wayHere is the site - you can see the schedule and the station it takes you too.http://www.washfly.com/coach.html