The Orange County Children’s Book Festival celebrated its 10th anniversary this year, with the September 29 event drawing close to 40,000 attendees to Costa Mesa, Calif., campus of Orange Coast College. Mrs. Nelson’s Book Fair Company, the institutional arm of Mrs. Nelson’s Toy and Book Shop in La Verne, Calif., handled sales for the festival, which featured more than 100 authors, illustrators, and storytellers on five stages. Here, a sampling of photos from the day.