As many of you surely already know civility is required on StackExchange:
Civility is required at all times; rudeness will not be tolerated. Be nice.
Treat others with the same respect you’d want them to treat you. We’re all here to learn together. Be tolerant of others who may not know everything you know. Bring your sense of humor. Be honest.
Above all, be honest. If you see misinformation, vote it down. Add comments indicating what, specifically, is wrong. Provide better answers of your own. Best of all — edit and improve the existing questions and answers!
From the FAQ
Please take this as a gentle reminder that we expect a certain quality of behavior as well as a quality of content. This has many reasons; attracting and maintaining new users is certainly one, but really it's about the kind of community we want to be.
On this note the moderation team will be deleting comments and editing out rudeness in questions and answers. Please be nice in your own posts, and if you see rudeness on the site, old or new, edit it out (or flag it if necessary).