You could try to contact trulia but my guess is you can't post the listing because you are not a real estate agent/broker. One way to keep costs low as a FSBO is to do an Entry Only listing which will give you access to the MLS via a real estate brokerage and therefore Trulia.
Territory Real Estate
Massachusetts #1 Brokerage for Home Buyer's
617 848 5407 ext 704... more