I've used the metro on a trip 7 or 8 years ago and don't exactly recall how it works. I have the maps and schedules and can see the fares but I'd be interested in a description of how the entire process works.
Do you swipe a card going into a station and then swipe the same card coming out for it to determine exact fare? Do you just select an exit station when you're going in and it's checked when you're coming out?
I see I can buy farecards online and that might be convenient so I don't have to handle that on my first trip with the whole family (2 adults, 2 kids).
I'd also be interested in whether the metro would be recommended over a cab trip from Reagan Natl to the Mandarin Oriental when we arrive with luggage, etc.