What music theory book do you use with your students?

I'm just a High school student...A first year music theory student at that...So my comment may not interest you, but...At my school, our director uses Master Theory books 1-6 by Charles S. Peters and Paul Yoder...They are very helpful for people that are basically diving into music, or students who'd like to learn more about music...Hope I might have been able to help you and your quest for teaching Music theory!!! Good luck!

I tend to combine a few books ideas not only use one book! Its too limiting to stick to one book. Create your own syllabus and go to your local sheet music store and spend an hour browsing. You know what your students need to learn and then you can change it when you need too.

Eta Cohen (Levels 1,2 & 3) Suzuki ( A whole different method, but good anyway)

For beginers, use 'All For Strings.' I'm not sure for piano.