Alpha Oops by Alethea Kontis and illustrated by Bob Kolar is a fun, light read about the day when Z (and the rest of the letters) decided to change things up a bit when it came to the alphabet. A, the natural leader, had some issues to work out, of course. He didn't like being bossed around by the letter Z. But all works out rather well in the end. It's a comical read that "kids" of all ages will enjoy.
I think this story would pair well with Chicka, Chicka Boom Boom by Bill Martin Jr. And it is especially appropriate for this time of year--back-to-school.