Video is a very literal format, so you should never begin to produce any digital video content without an idea as to what the story is. This can be very difficult for most people to do, especially when this involves real life footage. The best way to transfer a vague idea into a clear story arc is by using a storyboard.
A storyboard is supposed to be a visual realization of your shot list. For every scene you create a shot list, and then make a picture interpretation of these shots to construct a vision as to how the visuals will tell the story. You do this for every scene, and then you can hopefully see what is important, how it looks, and how these images work to shape the story arc.
Chart the Project
To create a storyboard you have to first diagram the pieces of your film. For each type of video project this will be different, but essentially there are some very specific story elements that are true of all media. You begin with establishing action or sequences, which are set to either identify the characters or the event that will be taking place. Then you give shots of the beginning of the story, which can be interpreted as the rising action. This may be your son getting ready for his football game. In that case you would show shots of him practicing, getting ready, and heading to the field. The middle is where the main action takes place, and most likely where most of your shots will be. The end is the summation of the event or story, where the characters are re-established and shots focus on them removing themselves from the action that has just taken place. You should also put in second unit or B-roll shots, such as cut always to images that are not directly part of the storytelling.
Here you try to diagram images that satisfy the needs of each section. This means getting together a number of establishing shots of locations and of the character's primary behavior for the first section. The beginning of the story needs to give enough images of the coming action as to note that the audience is about to see something that is not part of standard day-to-day life. The middle is easier because every visual should be designed to simply show you what is occurring in the clearest, and most interesting way possible. The end does the reverse of what the beginning does, and here you put images that return the characters to their standard world.
For each of these chapters create a panel system that shows the type of image it is, what angle and shot type it will be done at, and any other visual element you want for that shot. Do not do too many panels, as you want to be able to have some spontaneity when you are actually in production on location. From here you take these panel drawings and use them as the basis for what you want each shot to look like.
Trial and Error
This is a very simple method for constructing a storyboard, and there are larger and more specific styles out there. Try being as basic as possible at first, and once you have done it a couple times you will know what you need from the storyboard.