I've been using MyBB since 2009, so I guess I've got enough experience to help everyone with their problems. Note, that I'm a web designer and not a developer. I can help you with your theme and general forum problems, but not plugins, since it's just not what I'm doing.
Some rules:
You can ask whatever you want as long as it's related to MyBB.
Do not answer any questions of other people and make your own thread.
If you want a specific tutorial about something, just ask for it.