Complex sentence: Davis spent five years researching and writing the book, conducted over 200 interviews of many people involved with the production of the show, and worked with the cooperation of co-creator Joan Ganz Cooney.
Split into simpler sentences: Davis spent five years researching and writing the book, and conducted over 200 interviews of many people involved with the production of the show. He worked with the cooperation of co-creator Joan Ganz Cooney.