By far, the best book that my husband and I have found on parenting (other than the Bible) is Shepherding a Child’s Heart by Ted Tripp.
The first half of the book, the author lays the theological and philosophical foundations of parenting. He also takes a chapter to review some of the most common, yet unbiblical methods of parenting (i.e. pop psychology, behavior modification, emotionalism, bribery, manipulation, etc.). Then, he spends the last half of the book building upon the foundation previously laid and offers very practical insights and suggestions to aid in implementing biblical principles of parenting.
I cannot recommend this book enough. It has been so instrumental in helping to formulate my own perception of my role as a parent (as the title of the book really says it all: “Shepherding a Child’s Heart”). For those who are seeking to be more than just a “guardian” to their children, or those who want to really help shape and influence their children’s heart eternity, this book is a “must read!”