Note (6/22/14): These cards & rules are a bit out of date. The new rules can be found here, and the new version of rules cards can be found here.
I have made the following document for Crazier Eights (First Edition) to explain all the rules needed to play the game. The Game Crafter charges a great deal of money for a rulebook and they shuffle the rules cards into the deck in a way that customers could find confusing. I am thinking that using a document (a piece of paper) for the rules is the best way to go (perhaps in addition to one or more rules cards).
The document can be found here: crazier eights rules document.
The document is a somewhat brief/abridged version of the rule book I wrote a while back.
This more brief version of the rules is almost identical to the rules presented on these rules cards:
A more detailed version of the rules can be found here.