Well, lets start with the rules.

Lets start with just 5 rules and see how that goes. Pick the 5 most important and keep them as short and to the point as possible.

Examples:

1) Do not kite without proper training.
2) Please do not jump or ride near shore
3) Please roll up lines and secure kite when you are not riding
4) Please do not park or sit near launch areas
5) Watch chidren at all times

Change these however you feel fit... it's just an example.