In his autobiography Bill Peet says: "It was a wonder I could write much more than my own name after drawing and daydreaming through English classes in grade school and high school. I do believe what gave me the language was my love of books and the hours of reading many of the best authors over the years, starting with those animal books in the neighborhood library." "My favorite animal stories were by Ernest Seton-Thompson, a naturalist who illustrated his own books." Wahb-Biography of a Grizzly was one of Bill's favorites.

Bill "absorbed the language" in books by James Thurber, O. Henry, Zane Grey, and the stories of Jack London, Mark Twain, Jules Verne, Charles Dickens, R. Kipling, and R. L. Stevenson. Some other influential authors included Sinclair Lewis, H. G. Wells, John Steinbeck, Thomas Mann, Upton Sinclair, John O'hara, E. B. White, Erskin Caldwell, George Orwell, Edgar Allen Poe, Victor Hugo and James Fenimore Cooper. He also read the New Yorker magazine every week for over 40 years.

Titles he singled out included Beowolf, Gone with the Wind, Ivanhoe, Raintree County, The Three Musketeers, Robinson Crusoe, The World According to Garp, Andersonville, and several biographies including one of his favorites, Carl Sandberg's Abraham Lincoln: The War Years.