Here are some additional resources to use once you have started the project:
Review: Plan of the Milton Cemetery compiled from survey by William and Breck, Engs. 1877
Read: Graven Images: New England Stone Carving and Its Symbols
Read: New England Gravestones and the Iconography of Death
Read: Iconography of gravestones at burying grounds
Read: Field Guide to early american gravestones in New England
Read: The Plymouth Colony Archive Project Regional Studies of Mortuary Customs in New England
Read: Review Essay Early New England Gravestone Scholarship
Read: pp1-12 from Gravestones of Early New England by Harriette Merrifield Forbes