When you research existing documentaries, it is useful to take screen shots of interesting shots. You can then open up the storyboard template from within the 'Pages' software program. Next, annotate the shot types and how their choice creates the narrative & message of the doc. Remember the textual analysis skills you developed when studying TV drama. Comment on:
shot types, camera angles, mise-en scene, sound, SFX/graphics

When you have completed it, screen shot it again. It will automatically be saved as a PNG file on your desktop which you can then upload to your blog as an image.