Trail 56 and the trails around it are the best, but there is 140 miles worth of exploring to do. the North Brookfield section is good too.
Take a left 10 miles if heading south of Waterville off Route 12, or a right if headed north of Sherburne. This is Larkin Road and you'll go over some huge hills before getting to a "T" in the road about 5 miles out. Take a right and go 300 yards and take a left onto a seasonal road. Stay to the right at the graveyard about 1.5 miles in and the station with maps is up about another 300 yards.
http://www.singletracks.com/item.php?c=1&i=906