I have just finished reading Dr. Charles Tart's, Mind Science: Meditation Training for Practical People - which I highly recommend, along with his website, which is a treasure trove of information related to meditation and a host of other related topics:

http://www.paradigm-sys.com/index.cfm

From the homepage: "Dr. Charles T. Tart has been involved with research and theory in the fields of Hypnosis, Psychology, Transpersonal Psychology, Parapsychology, Consciousness and Mindfulness since 1963. He has authored over a dozen books, two of which became widely-used textbooks; he has had more than 250 articles published in professional journals and books, including lead articles in such prestigious scientific journals as Science and Nature, and provides regular public speaking appearances."

I hope you find this of value.

John