Seriously? The absolute best way to learn is to play a mission, and then open it up and look at it. This way you can see the scripts, waypoints, triggers, etc. in action. You can then copy and paste that script into your own mission folder, make some adjustments and see what effects those changes have in game. Use this method combined with the biki and/or comref here on our sitemap and you will soon grasp an understanding of how things work behind the scenes.
Might I also add that playing other missions can help inspire you to even greater heights. Happy editing.