The Winslow Boy (1999)
Frequently Asked Questions
Not a book but a 1946 play by Terence Rattigan, also called "The Winslow Boy", which is still available. You can read a detailed description at the Wikipedia: http://en.wikipedia.org/wiki/The_Winslow_Boy. The film script keeps close to the original text of the play, only moving a few parts of dialogue around, and adding a few sentences in the very last scene.
Yes, the film and the play by Terence Rattigan are based on the case of George Archer-Shee.