http://www.chapa.org/housing_lotteries.htm (I did work this thru with a relative of mine and I know that realtors are not used.)
However if you want to consider MetroWest once you do your duediligence - I would be delighted to help you out anyway I can!
The Massachusetts Housing Department (Mass Housing) has great programs for first-time homebuyers! Not only that, but in order to be accepted into one of their programs, Mass Housing insists that the potential new home-buyer take part in a course that covers everything a new home owner will need to know from the initial offer on a house, to the closing process and things that you will need to know during your first year as a new home owner. I had a client buy a beautiful home in Reading, MA last spring through a Mass Housing program and things could not have gone better for them! Best of luck and feel free to contact me if your search leads to the Melrose area.
Each City/Town has there own way of handling these situations and it really relies on what funding they get from the State and Federal Government. The best place to start out is at the City/Town hall or Community Development office.
I know from working on the North Shore that Salem has two very aggressive first time home buyer downpayment assistance programs. I don't know if Salem is a possibility for you but if you want me to e-mail you the information, let me know. Best of Luck!