I love this biography of John Lennon, John's Secret Dreams: The Life of John Lennon by Doreen Rappaport, illustrated by Bryan Collier. The illustrations are strewn with lyrics, which is always nice.
To enhance the experience, I've been showing Ed Sullivan clips along with other fun Beatles videos.
I love my job, but a little part of me dies every time a kid says gleefully that Big Time Rush (who? what?!) is better than The Beatles. HA! They were trying to get me and they did.