180 Essential Vocabulary Words: Independent Learning Packets That Help Students Learn the Most Important Words They Need to Succeed in School Book

This book is cited in nearly every more recent book I've read that addresses grammar instruction, so I had to read it. Not a read and apply type of teacher book, but it definitely addresses theoretical foundations behind grammar instruction.
It does include some application with sample lessons in the appendix, although if application is really all you want, I would look elsewhere (Jeff Anderson or Janet Angelilo). Still, it was a good read if you want more detailed information on research and theory. The chapter that compares behaviorism with constructivism along with Hunter's lesson design vs. mini-lessons (a la Calkins and Atwell) was fascinating.