We have just received a beautiful new edition of the 1648 Cambridge Platform from Skinner House Books. The text of this formative document -- the so-called "constitution" of the Congregational Way -- is supplemented by a preface from the editor, Peter Hughes, and a very clear and accessible introduction by Alice Blair Wesley.
It's a key text of our tradition, now available in book form, for a mere $8.00! I encourage every Congregational church to purchase at least one copy. They're available through the UUA Bookstore, either online or by phone (1-800-215-9076).