I can simplify all pot etiquette down to two rules:

1) Don't get caught. Seriously. If you get caught, you're gonna have a bad time.
2) Treat others as you would like to be treated yourself. Basically, don't be a dick. Share your weed, don't bogart, don't waste weed, and be thankful when others share their weed with you. If nobody acts like a dick, everybody can get high and have a good time. That's what cannabis is all about.