I have the Black Market, Envoy, Walled Village, Governor, and Stash promotional cards for Dominion. They didn't come with any rules. Where can I get the official rules from Rio Grande Games?
http://wiki.dominionstrategy.com/index.php/Promo. This page links to all promo cards, each page quotes the official FAQs. Note that there are no special "rules" associated with the promo cards, in general what you need to know to play them is on the card text. But there are official FAQs/clarifications, like there are for every card. They should have come on a sheet with the cards themselves.