The Lakelands Trail is a 20 mile trail with 6 miles paved (currently, more coming). 

This trail has a nice surface, although it does tend to collect clutter from the overhanging trees.  It also runs directly past the Zukey Lake Tavern, which might provide a nice opportunity for a refreshments break.

I think the trailhead in West Bennet Park off of Merrill Road is the best place to park.

Here is a map which shows the rough location of the parking lot, which is on the West side of the street (across from the Hamburg Township library and offices):

http://tinyurl.com/LakelandsTrail-MerrillRd-Lot

The address is roughly 10350 Merrill Road, Hamburg, MI

There is a small paved lot on your right as you pull in. If you go left (South) on the trail there are port-o-potties in the field a few hundred yards away. If you go right (North) you will intersect the trail immediately after the railroad tracks. The spur from the parking lot to the main trail does have a bit of a downhill, but also has a reasonable runout before you need to turn onto the trail.

Here's a resource page for the trail: http://en.wikipedia.org/wiki/Lakelands_Trail_State_Park