Like Bob, I'm in the upper lakes, so don't have any resources for your area. Other than to recommend The Great Lakes Cruising Club. For a modest fee you get access to all of their harbor/anchorage guides, which are super-extensive. We've found very few places that are in other guides that aren't in the GLCC archive.
However, a very highly recommended book for when you get up to Northern Huron, is "Cruising the North Channel" by Kenneth McNeil Wells.
It's from 1960, so some info may be outdated, but the anchorages and rocks (mostly) don't move. It's worth it just for Wells' beautiful prosaic writing.
In Lake Michigan "Summer Sail" (1984) by John Torinus is a great guide to the Green Bay area.
And "A Gunkholer's Guide to Northern Lake Michigan" (1982) by Patrick and Judy Nerbonne is great for the northern islands.
I believe all 3 book are out of print, so you'll have to find used copies.
Until very recently, with the new 5th edition, any edition of Bonnie Dahl's book was hard to find and used copies were sometimes outrageously expensive.