When I work on a book I use a storyboard to keep me on track. In the beginning stages it is mostly concept sketches that I paste into place to see how the rhythm of the piece is flowing. This is a look at the early stage of a book I am working on. Like other illustrators, I don't always go from page to page in order, but skip around depending upon difficulty, use of models, time to get good reference photos and changes in the general tone of what I am trying to achieve. 
An occasional image may be in color here and there, but the bulk of all the color finishes is done after the sketches have been approved by the editor.
My storyboard is like a mini dummy. Once I have everything in place, I'll construct a working dummy and submit it to the editor for any changes or suggestions. In the meantime I have a few months... (*weeks) to complete the initial sketches.
For this story I needed to get lots of first hand photos of a nearby town. I photographed stores, parks, streets, vehicles and people for several scenes I need to create. I needed a number of young students as models for characters as well as adults for some crowds in the story. Children in my Sunday School Classes and adults in our church are great subjects because there is a whole community of folks to choose from. I think they will enjoy seeing themselves in a book. The hair color may change, or the face might be a bit different, but I'll be sure to let them see where they are in the book.
