During September 2010, my brother, Sophus, and I biked the Paul Bunyan Trail in Northern Minnesota, and the Lake Wobegon Trail in Central Minnesota. Both are rail-to-trails and paved, so they make for easy biking.
The Paul Bunyan Trail is 112 miles long and winds between lakes, forests, and some farm land. It runs from Baxter on the south end to Lake Bemidji on the north end. Web sites that contain information and maps about the trail are:
Trail Maps and DNR Official Trail Site

The Lake Wobegon Trail is officially 28 miles long, but my brother and I did a round trip, biked the spur toward Holdingford, toured St. Joseph, and did a small amount of off-trail biking through other towns. Thus our total was 88 miles. The towns along this trail are typical of the towns Garrison Keillor used to model his legendary Lake Wobegon after; hence, the name for the trail. Of particular interest are the large cathedrals that are in several of the towns. Web sites about this trail are:
Great Bicycle Trails, Lake Wobegon Trail,, and YouTube of Dedication

The links below have photos taken along these trails and will give you a good idea of what to expect should you be interested in biking either or both. Well worth the ride!