Most people don't realize how much work goes into an illustration even before the first rough sketch is done. When I get a manuscript I get ideas for the pictures almost immediately but then I realize that there might be certain details I need to reference so that the objects I draw look accurate. Remember, even a cartoon version of something needs to look like that thing so young readers will recognize it or learn what it looks like. I'm working on a project that involves a raccoon and native american indians of the North East US so research for reference photos and descriptions were needed for the characteristics of the people, the landscape and environment, the various seasons, clothing of adults and children, native plants, cooking methods, maple syrup making process, utensils, storage pots, cradle boards and dwellings. When you look at the illustration and it looks like the situation presented is just naturally happening...I've done my job.