The Sudbury is a slow flat river that meanders its way up through the countryside west of metro-Boston. It begins somewhere south of Framingham, but the put-ins are primarily in Sudbury and Lincolon. There is a tight spot off of Lincoln Road in Sudbury to put into the river, but the main put-in is in Lincoln off of Route 117. There's a nice dirt parking lot, which is not too far from the water. The Sudbury River winds through the Great Meadows Wildlife refuge, and it is not unusual to see Blue Herons, turtles, and other wildlife on the banks of the river. The Sudbury River curls into a wide estuary, turning a curve to join the Concord River. You can get out (or also put-in) just under the Heath Street Bridge, or just keep paddling downstream to reach historic Concord to sail under the historic old North Bridge (echoes of Revolutionary War gunshots!). Just before this point, the Assabet River from Maynard flows into the Concord River, and the river courses on to eventually join the Merrimac River (that's another trip altogether). It's a very idyllic and peaceful time on the water with very little civilization at any point along the course of the river. You realize why Thoreau settled at Walden Pond as you slowly paddle downstream here.
It's rural in this part of the country. There's a bed and breakfast down the road, but I've never been there. Probably have to stay at a hotel along route 128.
Best way to get to the Sudbury River is by Route 117, drive west from route 128 to the town of Lincoln. Put-in and parking lot are on the right (look for sign). If you go across Lees's Bridge, you've missed it. Otherwise, from route 495, take 117 east towards Lincoln, parking lot is on left.