Michigan rail trails guide
 

Here is the online edition: Trails Michigan - Home Page
I see a few new rail trails I plan to ride this year. I ride the rail trails 95%.

Also, if you go to Google Maps, and click on the little bike (instead of the car, walker, or train) and zoom in somewhat, you can see many bike trails. It's pretty good.

The full "Michigan Trails" publication is a really great magazine that's been growing the last few years. It started out just as "West Michigan Trails" or something like that, but now covers the whole state. Lots of maps and good info, ads from trail-supporting businesses, etc.

I've seen it at those tourist info rest stops and other places around the state (haven't seen the 2014 edition yet).

Same here, mostly rail trails. Can't wait for better weather. I also have to find some new trails...did most of them in MI, few in IL, IN and OH. It's the best way to spend a day or two!

Yup, pretty good, but far from being perfect. It doesn't show some trails, and shows some trails that doesn't exist or are in terrible shape. It's always a good idea to check it with few sources before going.