The Colonial Coin Collectors Club (C4) publishes a newsletter, a series of scholarly monographs and has a very active e-group. They also host a annual convention with a major auction in Boston (during November). Many colonial collectors and dealers from around the nation attend.
The Colonial Newsletter (CNL). The American Numismatic Society publishes this quarterly research journal covering on all aspects of colonial numismatics. See their website at:
http://www.amnumsoc.org/cnl/