Where do you purchase metro tickets? Do hotels sell them, or are there kiosks in the metro?

There are vending machines at most - if not all - stops, as well as staffed booths at many. Info online at www.wmata.com/riding/faresales.cfm

There are machines at each metro station to purchase passes. As a tourist you may purchase an all day pass for $5 that gives you unlimited access which is most economical.

We used a credit card in the machine - you pick a certain amount to be loaded onto a ticket and then insert the ticket into a machine when you board a train - it deducts the fare and leaves you with the ticket.

Actually, you have to run the pass through the turnstyle's card reader both entering AND exiting -- it's the exiting that deducts the fare, depending on how far you go (and whether it's rush hour).

And my daughter's friend learned the hard way -- do NOT put your pass in the same pocket as your souvenir magnet.

I bought my ticket online a few weeks before my trip.My 20.00 ticket served me well for three days.

The "staffed booths" do not handle money nor Metrocards ... they're there only for security and information, altho they will help you purchase your tickets. Make certain you're not using too big of bills, as there is a limit on how much change the machine will return. Some (but not all) of the machines accept credit cards.

Some hotels do indeed sell the cards, but most cards are sold in the stations.

You can purchase in advance at www.wmata.com, with no postage nor handling costs. I've also seen partially used Metrocards sold on EBay. Be aware that there are "per-ride" cards, and the unlimted "Visitor Pass" and similar offerings. The "Visitor Pass" is not usable before 9:30 on weekdays. We purchased a 7 day "short trip" pass that was good at all times, but during peak times covered only the first $1.70 (I think) of any trip ... if your ride exceeded that you'd have to pay the extra amount in cash ... we never had to pay any extra.

Now that you have all this good advice - one more thing. We found the Metro to be incredibly easy to understand, well marked - good signage, clean. So this is probably one thing you don't need to sweat too much about DC