Think of storyboarding as a comic book. Every frame is a shot that you want to see, from whatever angle you want, arranged in order as they happen in your script. You don't have to be a great sketch artist to do a storyboard, stick figures are still better than nothing. The point of the storyboard is to organize your thoughts, your visuals in to a manageable shot list for your script so that when you get to your location, you're utilizing your time effectively. It's also a great way to see if your shot ideas flow, and if they do your rough cut for editing should go a little quicker.
Storyboarding is a great tool for your preproduction. As for tutorials.. here's a pretty good one with templates. It's not a video, but chock full of great info all the same. Storyboarding Tutorial
It's where your vision as a director comes into focus. The way I do them, when you are done, you should be looking at a representation of the final edit of the film.