Here's a little video I put together explaining the basics of the new "Question" feature in the comments system. It's pretty important that you understand it, so please take five minutes to watch the video.
I did this very off-the-cuff, and one topic I didn't address was who deals with categorizing the questions. The answer is: the moderators. You don't have to worry about what category a question belongs within; just pose (good) questions and provide (helpful) answers to the questions of others! Here's the video: