You must book your own accommodations.  A useful website for hotel listings near the convention center is http://www.hotelplanner.com/Hotels/42187-NEAR-Walter-E-Washington-Convention-Center

In the past, participants have stayed at the following hotels:

Hampton Inn Convention Center in Washington
1-800-230-4134
901 6th St. Nw, Washington, DC 20001  (Downtown-City Center)

Hostelling International Washington Dc in Washington
1-800-997-5148
1009 11th St. Nw, Washington, DC 20001  (Downtown-City Center)

Red Roof Inn Downtown Dc in Washington
1-800-997-5149
500 H St. Nw, Washington, DC 20001  (Downtown-City Center)