Put in at Dowses Beach in Osterville, cross East Bay, and follow the river. Be careful to avoid the shipping lanes and boat traffic, as it can get crowded in the summer months. If the Centerville River seems too crowded for your comfort, half way up you can turn left under the bridge and paddle up Bumps River into Scudder Bay. Both Centerville and Bumps River end in a marshy area, so it will be clear where it ends. These paddles take about 3 hours roundtrip depending of course on tides, traffic, and how fast you are paddling.
Put in at Swan Pond in Yarmouth. Cross the pond and follow the river towards the ocean. There is a bridge under Rte 28 halfway down that you can manage to cross at low tide, but be aware of the tides because if you return at high tide you'll have to cross the road with your boat! The river is a mellow and beautiful area, with an osprey nest and several opportunities to observe the wildlife. It should take about 2-3 hours round trip.
Hathaway's requires a Barnstable sticker or $10. This pond is a great place for beginners. The pond also has walking and running paths along the outside. It's flat and pretty small, so you can practice crossing the pond or follow the edges to practice your turns.
This is another good flat pond for beginners. It's fairly large and does not get as crowded as Hathaways. The beach requires a Barnstable resident sticker, but there is a fisherman's landing with a small sandy area that anyone can access.
Prince Cove is a scenic paddle for kayakers of all ages and abilities. Osprey towers, flourishing marshes and a hot spot for catch and release striper fishing, Prince Cove is one of Barnstable's best kept paddling secrets. This calm estuary is a great place to bring kids and adults for a memorable paddle or a glimpse of what makes a Cape Cod summer so special.