After discussing this issue among the moderators, we all agreed that posting guidelines is something that will be useful to everyone on the Forum. Taking all your suggestions into account, I have created this pinned post in the Help channel that will hopefully be visible to new users, but will also give more senior users an opportunity to direct new users to an official guideline.
Please note that these are not hard set rules, but are called guidelines for a reason. We appreciate your continued support in making this Forum a welcoming place for everyone!