There are a few year round rentals available in Marshfield. I would be happy to help you with your search. Contact me at (781) 363-0485. Let me know how many bedrooms you are looking for etc.
http://www.trulia.com (Rentals Section)
http://www.zillow.com (Rentals Section)
http://www.realtor.com (Rentals Section)
Between all of those, you will get a very clear picture if you can find what you are looking for. Good luck!