To get to the DoubleTree in Rockland if you are coming from Boston: take 93 South bound to Rt 3 southbound. Take Exit 35, and the hotel is about a quarter of a mile off the highway.
You can also get to the hotel using the Hyannis shuttle from the airport, which drops off about a 15-20 minute walk from the hotel (or a very quick ride!)
To get to the venue using transit: you can take the greenbush line from south station to the North Scituate stop. This is then a 10 minutes/lyft from the Barker House.