The main concourse at Cobo runs north/south with the showrooms running off of it to the west. Signage is somewhat poor within the center; so, if you ride the People Mover, realize the stop is on the north end of the center on the 3rd floor, two floors up from the showrooms. This year, Michigan Hall contains some exhibits as well. It is located down an escalator at the south end of the main concourse.
Cobo Center's Interactive Floor Map should help you out, as well as the 2010 NAIAS Exhibit Floor Plan.

