I saw a user on SO today that has asked 32 questions on the site, but that's the extent of the user's total activity. The user has awarded no accepted answers (so 0% accept rate), no comments, no edits, no answers to other questions, and not even any votes. This appears to be the sort of user who Jeff would say "is not engaged with the community".
I was going to try to point the user to the faq, but the official faq says nothing about how to use the site. It describes what kind of questions to ask (that's a good start), a reminder to be nice, has some stuff about reputation levels (new users will glaze over this because it's not relevant to them), how bounties work (more of an intermediate user thing, since you need some rep to even start), a few other bits and pieces and that's about it.
A description of the normal question-feedback-accept workflow might be appropriate. Here's a quick attempt:
How do I ask questions here?
When you post a new question on Stack Overflow, other users will almost immediately see it and try to provide good answers. This often happens in a matter of minutes, so be sure to check back frequently when your question is still new for the best response.
If your question needs clarification, you will see comments in smaller type below your question. If other users ask you for more information, edit your question with the "edit" button just below your original question. Providing clarification promptly will help get you the best answers.
As you see new answers to your question, vote up the helpful ones by clicking the upward pointing arrow to the left of your question. Answers are normally sorted by vote count so the most highly voted answers float to the top. Other users will also vote on the answers to your question.
When you have decided which answer is the most helpful to you, mark it as the "accepted" answer by clicking on the check box outline to the left of the answer. This lets other people know that you have received a good answer to your question. Doing this is helpful because it shows other people that you're getting value from the Stack Overflow community. (If you don't do this, people will often politely ask you to go back and "accept" answers for more of your questions!)