As a newcomer here, not knowing the culture, it is easy to make some mistakes. Due to the complexity of the site it is also sometimes difficult to find the information you need when you need it. This "Question" wants community input on what the newbie needs to know. I hope that eventually it can be collected into a FAQ that can be offered to newcomers when they create an account here.
Screen Names vs Real Names (and respecting anonymity)
Some users create accounts under a real-world identity and are happy to be known here with a real name. Others prefer to be anonymous, using a screen name instead. There are many reasons for wanting to separate your true identity from your local one, including employers not understanding how you can contribute so much here. If you haven't yet joined officially, give some thought to which model you want to follow.
However, a strong community standard here is that you don't reveal the true identity of a user who uses a pseudonym. You may know the person, but don't reveal their identity here.
Moderators and their purpose/powers
Moderators are appointed or elected from those who nominate themselves or are nominated by others and accept those nominations. They have some extra powers, but also are here to give advice in the Classroom and other chat rooms.
Initially, high rep users are often seen incorrectly classified as mods because of the privileges they are given. A list of privileges and the rep required to obtain them, and the ones you already have can be found in the help center.
See the meta Stack Exchange FAQ: Who are the diamond moderators, and what is their role?
Why are questions put [On Hold] and what the poster should then do.
There are various reasons that users who have earned the close vote privilege will vote to put a question on hold. Usually it is because some number of them is confused about the intent of the question originator and think that the community will find it confusing also. It takes 5 close votes to place a question on hold. If you have a question of yours closed or placed on hold, you can either attempt to clarify it, or if you want to talk to a more experienced user you can go to the Guidance Office where someone will probably be able to help.
Having your question placed on hold is not a judgment. It's a way to help save your question from deletion. The only thing that happens to an on hold question is that it is locked from getting new answers. This gives you more freedom to edit without worrying about invalidating existing answers. On hold is supposed to be a temporary state, and once your question is edited it goes into the reopen queue for users who have the reopen privilege to review and see if you've improved it. If they deem it to be improved, they will vote to reopen your question. It takes 5 reopen votes to open a question.
See the meta Stack Exchange FAQ: What is a "closed", “on hold”, or "duplicate" question?
Our Chat Rooms
Here is where we
throw spitballs and paper airplanes, pass notes, play games on our phones under the desks, groan about work (well, we actually do that), and generally cause chaos do important site things like moderation. Lots of dedicated members hang out here, so it is the place to come initially if you have concerns. The mods and high rep members (i.e. addicts) will often be found here.
A room where you can go to get help with any question you may be composing. This should be used in conjunction with the question sandbox.
But if you don't find anyone in, try the Classroom.
Editing with Markdown, Latex, and MathJax, etc.
The main (site, questions and answers) accepts markdown:
You should probably look at that before writing your first answer. You should probably bookmark this or an equivalent.
Program code and simple math expressions can be presented with latex:
for example $x^2 = x * x$ is written \$x^2 = x * x\$
More complex math can be written in MathJax.
The local lingo
Slang Meaning Explanation ---------------------------------------------------------------------------- mod moderator like a trusted janitor OP original poster The one who asked the question originally. tag wiki the tags page not unlike wikipedia
A glossary of many commonly used terms on the whole Stack Exchange network can be found on Meta Stack Exchange.
When you contribute you get, or lose, reputation points. Points come with privileges. The system is designed so that it is easier to increase than decrease your rep. Unlike high school.
See the meta Stack Exchange FAQ: How does "Reputation" work?
It is best if you look around for a while before you try to contribute. Make sure you have read the help center, to know how to post good questions and answers on this site.
You should probably answer some questions before you try to pose a question.
You should seek advice, first in the Classroom (where many people meet) but also in the Guidance Office if anything offends you or you are mystified about anything.
If this is your very first time here, a tour of our site is bound to be useful.
The "Answers" given here should be suggestions for additional newcomer resources with appropriate links. Note that some newcomers are familiar with StackExchange generally, but many others are not.
You can also find a wealth of information here: FAQ for Stack Exchange sites