The racing rules are revised and published every four years by the International Sailing Federation (ISAF), the international authority for the sport. The current edition is for 2009-12 and is available in pdf version at:
It is a pretty dry read for most people, but an online video quiz can help the average sailor examine and practice the rules in a more real-world way.
Check out http://game.finckh.net/indexe.htm by Uli and Wolfi Finckh. Click on Easy, Medium, or Hard based on what kind of rules quiz you would like to try.
An example of situations will be like the one below. The red boat calls for room to tack and then dips below the green boat after blue tacks away.
After you decide the correct response you are scored and given the rule that covers the situation:
Just great sailing TV: