I made a flow chart of a 40K turn to get a better grasp of the rules. I'm not sure if it's of any use to others, but I felt I learned a lot making it. That said, 40k is all about exceptions to the rules. It's what makes the armies different from each other. If you're the kind of person who wants to know all the rules before playing, this can be maddening, as you would need to read every codex. Believe me, there are plenty of people who do this.
The flow chart is generic (it's the only way it could be made), so new players who might use it should know how their army makes exceptions to the rules. Let me know if you see any obvious errors or omissions. I intentionally used the rulebook only, ignoring codices. You're free to do whatever you want with it. It was made in Microsoft Visio, so ask if you want a copy. It was formatted to print tabloid (11x17).