Zen and the Brain - Toward an Understanding of Meditation and Consciousness by James H. Austin, M.D. - http://mitpress.mit.edu/book-home.tcl?isbn=0262011646
Mindfulness In Plain English - This book, by H. Gunaratana Mahathera, is an invaluable gift that you can use to inform your practice of meditation. The tradition is Theravadan Buddhist, but it is true to the spirit of Zen as well. The information is invaluable. "As more people - http://www.saigon.com/~anson/ebud/mfneng/mind0.htm
Windbell Publications-Dogen Sangha - Zen Buddhist Books from Windbell Publications, the publishing arm of Dogen Sangha, a Buddhist community based in Tokyo and founded on the teachings of Dogen Zenji. - http://www.windbell.com/