Here is a
link to the travel section of my blog. Scrolling through that may give you some ideas. I make a lot of weekend trips to the the lakeshore. Either coast will make for a nice trip, the west is especially nice with the Traverse City/Petosky area on the way to Mackinaw City.
Be sure to stop into a bike shop or the
LMB office downtown and pickup the MDOT maps for cycling Michigan, they identify the traffic density on all the roads. A fleece jacket and studded tires help get me through the winter.
Marc