How People Learn
How People Learn (Bransford, Brown, and Cocking, 2000) is a well-written and accessible introduction to how research, especially the learning sciences, can inform teaching and learning. The first author, John Bransford, was on my dissertation committee and wrote this book while I was in graduate school, so its ideas form the core of my knowledge about educational research.
Bransford, J. D., Brown, A. L., & Cocking, R. R. (2000). How people learn: Brain, Mind, Experience, and School: Expanded Edition National Academies Press. http://www.nap.edu/catalog/9853.html