Supporters guidelines from 2008 for amateur astronomers available in MSWord or pdf (so far we don't expect them to change much)
A sketch of the Maple Beach with some notes about the site from 2008 (I'm working on updating it for this year.)
Two important things about the site:
Pictures of the site are at http://www-personal.umich.edu/~aquilla/pictures/AATB09Prep.html (links at the top will take you to pictures from last year's prep and the event)
The public site is at http://www-personal.umich.edu/~dgs/kensington/
A map and directions are available at http://www.metroparks.com/parks/pk_kensington.php. Note there is bridge construction going on so there are several detaours from 96. The construction is expected to be complete by the end of July, but who really knows. The metroparks website above should have the latest info. There is a $4/vehicle park entrance fee (or $20 for an annual pass).