I became interested in Mindfulness after reading The Miracle of Mindfulness by Thich Nhat Hanh. His webpage is (oh well, google his name and Plum Village. I can't post links yet) and has lots of mindfulness excercises. He has written a lot of books, and you can usually find them at 2nd hand stores. His stuff is about midfulness from a Zen perspective and not specifically focused on the benefits of mindfulness as part of therapy, but if is teachings from people like him that influenced the rise of midfulness in therapy. He also has a lot of videos (again, I can't post links, but google his name). Jon Kabat-Zinn was one of the first people in western medicine to apply mindfulness to stress reduction and anxiety, developing a program he calls Mindfulness-Based Stress Reduction (MBSR)--google his name and MBSR and University of Massachusetts Stress Reduction program for links to his program and his research, and google his name for lots of videos from him about mindfulness.