The city is the only place to stay! Ann Arbor is not quite the same town in the summer between terms. Look at this fabulous place http://innonferrystreet.com/05/#
It is amazing, and it includes tickets to the Henry Ford. You don't mention if it will be a weekend or weekday?

It is sad that there is still that old perception of the city. You don't realize what you are missing, and how far it has come. It's not cosmopolitan or anything, but it really is a vibrant city. It is quite safe, not advising you to be complacent, but you can walk around at night downtown without too much worry. There are people everywhere downtown in the summer. Personally, I think Windsor is a big waste of effort.

Some great dinner houses:
Coach Insignia http://ae.freep.com/entertainment/ui...reviewId=16177

Opus One
http://www.planet99.com/detroit/restaurants/9783x.html

The Whitney (personal favorite)
http://www.thewhitney.com/

The 2006 Superbowl Venue www.fordfield.com gives daily tours

This is fun place too...not far from the Whitney
http://www.motownmuseum.com/

If you are looking for nightclubs or pubs, this is a great compilation:
http://www.metrotimes.com/metropolis/clubs/default.asp

There is so much more, but that should get you started!