Tom Nanos posted a report of his trip to Detroit on Obscar. The link to his website, which has the photos is
http://www.nanosphoto.com/gallery/index.php?cat=15
There are plenty of interesting locations in the Detroit area, but you need some help digging them out. Delray is certainly one good spot, but pay attention, it's not the greatest neighborhood.
Consider going to Toledo, about an hour south. There is a ton of railroad activity there, plus interesting waterfront locations. Or drive an hour north west to Durand and watch all the GTW activity where the lines cross.
Go to the Henry Ford and Greenfield Village or head up to Flint (an hour north) to Crossroads Village for steam.