The Plymouth Colony Archive Project at the University of Virginia: includes primary sources, maps, and undergraduate papers.
The Public Records of the Colony of Connecticut, 1636-1776, are all available on-line, with a searchable index.
The laws passed by the First General Assembly of Providence Colony in 1647 have been scanned and posted on-line in .pdf format, including the provisions against "whoremongers" and "sodomy."
The Mary Rowlandson captivity narrative is available on-line through Project Gutenberg.
The capital laws of Plymouth Colony from 1671 are scanned and available online.
A fantastic website that links to primary historical sources.