I had the pleasure of being an online graduate student at Florida State University where Dr. Driscoll was teaching. Having Dr. Driscoll as an instructor, using her own book as a textbook for the course, was an invaluable experience for me. Anyone who needs a deeper understanding of cognitive learning theories need not look any further than this book. The logical formatting and presentation, the examples and explanations of theory from a variety of sources, makes this book a true gem, and one I still refer to, years after attending Dr. Driscoll's course.
Just finishing my masters in secondary education, this is the book I find myself using as a reference most often. Just about everything is here in regards to the psychology of education from the elementry stuff like Behaviorism through a hoard of theorists like Piaget, Asubel, Brunner, etc. etc. etc. The contrast presented at the end of the book between Gagne and the constructivists makes the book feel particularly relevant.
Who knows, maybe it is just that so many of the other books for teachers seem lackluster (am I the only one who didn't find Wong particularly useful???), but Driscoll's book is one of the best reference books for teachers I've come across so far.
And yeah, I don't think it was meant as a 'reference' book per se, but this will definitely point you in the right direction and while it is certainly readible, I found it stood out most for me as a stepping stone to the literature.