I am just renewing our subscription to Lehman's Zoning Trilogy and wondered if others have heard of this resource. I admit not using it often, but our planners like it. This website was created out of the original "Zoning Trilogy", a three-part reference manual. The first part is a zoning dictionary, second includes samples of zoning provisions, and third are sample diagrams.
The website goes beyond that, having a question-and-answer section about zoning (useful for municipalities, for example), and there is a "zoning resources" section, with links to a lot of different websites.