The Radisson North Baltimore (formerly the North Baltimore Plaza) in Timonium, Maryland has 250 rooms on five floors with four elevators. Room rates are $99.00 a night (plus a 14% tax).
You can reserve your hotel room here. To put in the discount code, first enter your dates, then click "more search options," and you'll be given an option to put in a code. Use the code "chessi". After entering the code, click "search" and your room options will come up. Note: there is still a problem with pricing on the site if you put in more than 2 adults; choose 2 and you will get the correct rate.
You can also register by calling 410-252-7373. Be sure to say you are part of the Chessiecon convention to get the group rate.
NOTE: If you are transferred to corporate and told the block is full, try calling during normal working hours (Monday through Friday, 9AM to 5PM) to make sure you get the hotel directly.