The answer is: The author of Where the Wild Things Are is Maurice Sendak, who also illustrated the book as well.
You always capitalize the title of books and the authors name. With the title the correct words are capitalized. The only word that is not capitalized is the and that is because articles are usually not capitalized unless it starts out the title of the book. For example: The Chronicles of Narnia.
Hopefully this helped and good luck.
