Writing for children is not an easy thing to do. Keeping it simple and clear without being boring and patronizing means rewrite after rewrite until you get it right. And when you get it right, the book should work as well for adults as it does for children.
As far as I know, there is only one book written to help explain testing to children. And this is it, "I am A Bug".
Like all the best editions of the best children's books, the book itself has a joyous tactile feel to it, so that you want to pick it up and revel in the cover and packaging. Good sign #1.
The cover is simple, big text, big picture, embossed. And best of all the cover bug is smiling. Any testers reading it will appreciate the dose of good cheer that the cover alone brings to your day. Good Sign #2
Inside we are treated to a text working at different levels. Across the top of every page is a big text simple message, which when you follow it presents the story of "I am a bug". Every page is well illustrated by Catherine Sabourin. The pictures are simple and fun and can draw a smile from the most jaundiced and cynical of testers. Good Sign #3
And at the bottom of the page is an annotation for those of a slightly more advanced age or for the parent to read to the child. But nothing too complicated - testing is basically a pretty simple thing after all.
But as you are a professional tester, should you be interested in the book? Well, yes if you have children, then it is an easy way to explain your job to them. And yes if you have people of a non-IT persuasion that you would like to explain testing to. I haven't met any adult that didn't appreciate a short well written children's book. And yes if you enjoy reading something well written that has obviously been a collaborative labour of love for the authors.
I have read "I am a bug" several times; to remind me of the essence of what we do, to simplify my thought processes when things get too complicated, to drop off the baggage of the processes and methodologies that I'm currently using.
And most importantly, I read it because I enjoy reading it. Good Sign #4
"I am a bug" can bring some joy back into your perception of testing after a hard day's slog in a test environment.
But I would prefer to prescribe it as an in-process reminder, so that during what seems to be a hard slog, you pick up "I am a bug" and a few minutes later you are refreshed and smiling and no longer slogging.
"I am a bug" is brief therapy in a blue cover, and available without a medical prescription or referral.
For other resources on how to explain testing, check out James Bach's How to Explain Testing to Them and How to Explain Testing to Anyone but these are mainly designed for talking to IT adults and aren't as well illustrated.