Rebels Rescued: A Student's Guide to ReformedTheology is an excellent, concise introduction to the "Five Solas" and the "Five Points of Calvinism". It is a quick read with each chapter taking approximately 10-15 minutes. I found it to be Biblical, Gospel-centered, logical, and an enjoyable read.
Throughout Rebels Rescued, Brain Cosby utilizes a number of helpful word pictures to make doctrine more accessible to younger readers and/or those who have not been previously exposed to such teaching. He answers important questions like: "Why am I spiritually dead because of something they [Adam and Eve] did?" (pg. 18). The anticipated audience is teenagers, however, I think this book would be equally useful with the pre-teen age group. (Parents of younger readers may want to note that there is a reference to the sexual promiscuity of the church leaders on Page 9 and a reference to fooling about with sex on Page 22. ;) Furthermore, most of the "Reflection Questions" at the end of each chapter will likely be answered more easily by older students.
Rebels Rescued also serves as a gentle introduction to some opposing viewpoints and alternative interpretations of Scripture. For example, in his chapter on purposeful and definite atonement, Brian Cosby refutes the notion of "universal atonement" by looking at the context of key passages used by others to support the notion. Instead, he shows how passages like 1 John 2:2 perfectly dovetail with a reformed understanding of definite atonement. Brian Cosby does a superb job of refuting anti-Calvinist thought and successfully acquaints the reader with sentiments/arguments that are likely to be encountered as one moves into adulthood.
If you are looking for an introduction to reformed doctrine that is concise, yet thorough, you will likely find Brian Cosby's book, Rebels Rescued, a helpful starting point. With a little bit of history and a lot of Scripture, it is going to be my "go-to" book for young readers. Perhaps the best part is that the Gospel clearly shines through this book; we are all sinners in need of a Savior! A comprehensive understanding of God's glorious character and his work of salvation is essential to a faith-filled life. I'm so thankful for the way Brian Cosby makes these truths accessible to a younger generation! May God's Word, used liberally throughout this book, not return void!