- Christ Formed in You
- Broken-Down House
- Instructing a Child's Heart
- Shepherding a Child's Heart
I recommend these books and the others offered by Shepherd Press. I have used Broken-Down House for a small-group study which was highly profitable (and worldview correcting for some of us) and A Proverbs-Driven Life for a Sunday School study which was also very helpful. You just can't beat this price for great books!
If you do not own a Kindle e-reader, I recommend them highly: see here.
However, you do not need to purchase a Kindle in order to read Kindle edition books. All you need to do is download the FREE Kindle reading app. Enjoy!