For this Throwback Thursday I recommend: Harriet the Spy by Louise Fitzhugh.
Eleven-year-old Harriet keeps notes on her classmates and neighbors in a secret notebook, but when some of the students read the notebook, they seek revenge.
For amateur detectives, and readers who enjoyed Boxcar Children, Hardy Boys, and Nancy Drew this is a great classic! Harriet the Spy was first published in 1964, and like many of the Throwback Thursday Classics has also been adapted into a movie. We also have it available as an audiobook at the library.
You can find the book in the Juvenile Fiction section at J FITZHUGH and the audiobook at J CD FITZHUGH.