A Kids Book On Locks, But Good Info
This book is from a kit I got my son a year or so ago. Was thumbing through it yesterday, and thought it might be a good thing for beginners to check into just to see how a variety of locks work. No heavy details, just a 30,000 foot view.
The book is entitled "Lock It Up!", by Paul Beck, and is published by SmartLab. It is bundled with the Double-Security Safe Kit.

It is cartoony, only about 24 pages long, and written for children to understand. It lightly covers warded locks, lever locks, pin tumbler locks and combination locks. It also gives a quick history of locks, some light information on the difference between a fire safe and a burglar safe, even information on some of the security features on United States currency.

It even gives a basic overview of picking pin tumbler locks (though they needed an editor who knows that what is listed as "Tension Wrenches" are actually picks).

Not going to post any more pics, since it is copyrighted material. Just enough here to let you know that this book might be a decent gift for kids or adults to get an overview on how locks work.
Sorry if this sounds like an advertisement, but want to give credit to the author and publisher, as well as a way to find it, since I have added pics from inside the book.
Gordon