Diary of a Wimpy Kid is a realistic fiction novel written by American author Jeff Kinney, the first book in the Diary of a Wimpy Kid series, and is followed by Diary of a Wimpy Kid: Rodrick Rules. The book acts as a journal and follows the adventures of seventh grader Greg Heffley. The third book, Diary of a Wimpy Kid: The Last Straw, was released on January 13, 2009, and the fourth one, Dog Days, is coming out October 12, 2009. The fifth, My Last Year is due to come out in 2010. The book was originally on FunBrain, but when it was adapted into a print book, Jeff Kinney decided to split it into a series. The series has stayed on the New York Times Best Seller list for children's books for 17 weeks as of May 19, 2009.