The purpose of playing this campaign is to have fun.
General Tennants
No jerks. If you are acting like jerk on game day, don't come. How do you know who is a jerk and who isn't? Those who violate the mission statement are jerks. Everyone should do their best to both have fun and support the fun for all other players. Those not having fun or and/or spoiling fun for others will be asked to leave the campaign.
Communicate! If you have a problem with something, tell somebody. The participants are all adults (even if we don't always act like it in-game). Together we can figure anything out.
GMs and players should always be consistant within the storytelling. We can believe that in the world the sun rises in the west and sets in the east – but it should always do so. And everything that depends on that fact should reflect this. Don't contradict the consistancies set forth by other GMs in the campaign.
It is only common courtesy to let the GM and hosts know that you are not coming, so they know when to start and what to plan for. As soon as you know you aren't coming, let 'em know right away.
Players are encouraged to add “flavor” wherever they can. A good description of your PC, painting miniatures, a detailed PC background, some in-character fiction, or even helping to flesh out the campaign world are all welcome to all players – not just GMs.
If you would like to see a story or subplot – suggest it! GMs don't like doing all the work anyway. Alternately, offer to GM it yourself.
Be courteous to one another. Help the hosts prepare before the game and help clean up after. Take off your shoes when you come in the house. Ply them with snacks and gifts if you think it is appropriate. Happy hosts make for a good game.
GM's Guidelines
Anyone can be the GM if they want to.
Less is more. If you can have a multitude of items, choose a few that are really interesting and develop them as much as possible. Favor depth over breadth of content in all things.
Let the players make choices. That's what the game is all about. No railroading. At the very least give the players the illusion of free will. Instead of saying “no”, always consider saying “yes, but…”.
Try to keep adventure sessions reasonable in scope. Oftentimes even the best games can get too convoluted and out of hand if the GM tries to do too much. Try not to tackle “save the world” plotlines. “Save the nation” or “save the town” is about our speed. When in doubt, make the plot scope simply “save yourselves”.
Always try to add “flavor” to the game. Roleplaying away from a game session by email or IM is a legitimate way of getting a subplot out into the open between sessions. Also, it makes a good log entry in itself.
Try to build on previous adventures to create “campaigns” or extended stories made up of several game sessions. This continuity makes for a more immersive experience.
GMs should count on writing a session log after each game they GM or convince someone else at the game session (a player/bystander/pet/etc) to write it for them. Example templates of logs can be forwarded to you at your request. A GM post-mortem and campaign polls are good to in order to gauge the feelings of the players, but are not necessary.