There is pretty much one rule:
Don't be an asshole.
As for conduct on the road, I ranted about this once and have been able to refer back to it about once every eight months or so. For my quick reference, and any new riders, here it is:

I would like to make it abundantly clear that we are NOT, regardless of numbers, a critical mass. We are not out there to purposely get in the way of motorized traffic. We make our best effort to keep it to one or two lanes where applicable and we certainly do not plow through red lights. The way the FBC Spokane draws attention to the shear number of cyclists in the city and the need for better ways to get around is to follow the rules of the road. Nobody likes an asshole so don't be one. If you feel like you need to continue riding against traffic, purposely slowing in front of motorized traffic, going through red lights and otherwise making people angry with your bike, the FBC does not want you. Go get yourself run over on your own time, not mine. If you are hurt in a traffic accident while riding with the FBC and it is your fault, it will likely be the last FBC Fiasco and I don't think you want that. I certainly don't.
 Finger wagging over.