You need to produce a hand drawn storyboard for your production. This will be about 20+ frames that outline how you intend to shoot your documentary. It will include a clear idea of how you intend to frame certain interview subject as well as the type of cut away shots you intend to shoot. It is a planning document so there will be changes from your original drawings to the final output.
Examples of how storyboards work can be found here http://www.artistdaily.com/blogs/drawing/archive/2008/07/07/coen-brothers-movies-drawing-storyboards.aspx