What an educational psychology textbook ought to be: lean, focused, and with clear lines drawn between insights of cognitive science and instructional practices. It also does a good job of cutting through some of the faddish jargon that educational literature is prone to run off with before the science is well understood. See http://www.tantor.com/Extras/B0419_WhyStudents/B0419_WhyStudents_PDF_1.pdf for the book's figures, especially #21, which lays out the book's nine core principles.