Several good books have been written on the topic of Christian Education. Here are a few of my favorites:

Sowing for Excellence, by Claude E. Schindler, Jr., Association of Christian Schools Intl.
Inside America's Christian Schools, by Paul F. Parsons, Mercer University Press
Recovering the Lost Tools of Learning, by Douglas Wilson, Crossway Books
The Philosophy of Christian School Education, by Paul A. Kienel, Association of Christian Schools International.