Author Norman Bridwell and his wife, Norma, pose for a portrait in 2011. The creator of the Clifford the Big Red Dog stories died Friday at age 86. Charles Sykes/AP hide caption

itoggle caption Charles Sykes/AP

James Patterson, together with a cadre of co-writers, consistently produces more than 10 books a year. Forbes estimates that Patterson made $90 million this year alone. Janette Pellegrini/Getty Images for Disney Publishing hide caption

itoggle caption Janette Pellegrini/Getty Images for Disney Publishing