Formerly the Washington State Convention Center 

705 Pike Street - Arch Building
600s Meeting Rooms
Seattle, WA 98101-2350
Telephone: +1 (206) 694-5000

Seattle Sheraton Hotel is the official conference hotel.
1400 6th Avenue
Seattle, WA 98101

The Room Block is SOLD OUT.  The Sheraton may have additional rooms available here

Additional Hotels near the convention center here