Radio sailing uses the same racing rules as keelboats and dinghies ("the Blue Book"), with some small differences given in Appendix E: 

Exploiting the racing rules to their limits, as often happens in big boat sailing, is rarely beneficial. This is (mostly) because it is more difficult to judge positions and distances when you are not on the boat.

Here are a series of quiz questions written specifically for situations encountered in a typical Wanderers fleet sailing on our typical Wanderers course. They are aimed at newcomers and mid-fleet level sailors: Wanderers Rules quizzes

Here is an explanation of how the rules work for radio sailing, from John Ball (Canada). It inevitably strays into the topic of tactics: 

And here is a very clear explanation of the basic rules for radio sailing by Patrick Rynne. Recommended for anyone new to the sport, it also has some words of advice for big boat racers moving into radio sailing: