I wish Khan Academy had a brief tutorial on how to effectively use the site.  There are many things that users seem to often be confused about or misunderstand, and some users have said they would appreciate having such a tutorial.

Perhaps there would be a brief mandatory tutorial for new users, and a more comprehensive optional tutorial that is linked from that one and is also offered to any user if it's been more than a year since it was last offered to them. 
Perhaps a new user could wait to go through the tutorial for a week or 5 log-ins or until they want to make their first discussion post, so they have a chance to get used to the site before taking the tutorial.

Potential tutorial topics:

1. before posting a new Question, look through already posted Tips/Answers (both Top Voted and Recent); 
2. where to find the Community Guidelines;
3. where different kinds of posts (content questions, tips, mistake reports, technical problems, feature requests) are best made;
4. suggestions for getting the most helpful responses to a Question – and that responses are made by other users, so both use your critical thinking and respect their volunteered time & effort;
5. how to handle off-topic and inappropriate posts by flagging (include a link to any article about how flagging works);
6. if a mistake in a video has been confirmed by Khan Academy, there will be a correction box in the lower right of the video, but it will not be visible in full-screen mode, in the app, nor on YouTube;
7. A reminder that no Khan Academy course is intended to replace a full curriculum in the subject; any course should either be a supplement to a full curriculum for that subject or used just for informal enrichment.

If any of those topics have existing articles, a link to the article could be included.

I would appreciate others adding their thoughts about whether they would have wanted such a tutorial, and how they think it would (or would not) impact Khan Academy.