If you are looking for an easy (non-paved) hike while visiting Pictured Rocks National Lakeshore, Miners Falls is a great option. I visited the falls on a rainy/misty day and it was wonderful. The trail was lined with hundreds of wild flowers making for an added bonus on an already great trail.
If you are only passing through Munising, Michigan, one of the quickest ways to see Pictured Rocks National Lakeshore is to stop at the scenic overlook on the north west side of Munising. This overlook gives you a view of Munising Bay, Grand Island and Pictured Rocks National Lakeshore. After seeing this view I guarantee you will want to come back for more. We stopped here just after the sun popped out and lit up Grand Island. The water seemed to glow a deep blue and the fall colors on Grand Island were perfect peak.
If you area looking for great hikes to do in Michigan, make sure Sugarloaf Mountain in Marquette is on your list. This beautiful trail takes you to the top of the "Mountain," where you get a 360 degree view of Lake Superior, Downtown Marquette, and the Huron Mountains.