Chess Strategy for Children by David H. Levin is an e-book in the form of a "pdf" file. It can be opened (read) using Adobe Reader or other freely available software. (Click here to display the cover page as a "jpg" image, or here to download a pdf file containing two sample pages from the text.)
Here's some basic information.
Most chess books for beginners explain that there are principles such as "controlling the center." But this book, by presenting a series of positions along with many questions and answers, is designed to help the reader make the discovery that ideas such as "controlling the center" should be principles.
In the October 2011 issue of Chess Life for Kids, this e-book received a positive mention from editor Glenn Petersen.
Here are some young readers' reactions to the draft version of the e-book.
If you would like to order this e-book, click on "Availability" (in the "frame" just to the left) for information on how to send payment. Be sure to provide an email address so that I can convey to you how to create a copy of the e-book on your computer. If you would prefer that I email you the e-book as an "attachment," let me know and I will be glad to.