A new book by Namkhai Norbu Rinpochehttp://www.wisdom-books.com/ProductDetail.asp?PID=22489
I found it quite wonderful. An interesting detail is that Togden Urgyen Tendzin did 11 million prostrations and at least a full three year retreat on the Longchen Nyinthik Guru Yoga.
Let's also do a prayers for Namkhai Norbu Rinpoche that right now is in a hospital in Brazil.
"The direct, hard to understand, subtle field of knowing, the Great Path, is non-conceptual (akalpana), and entirely beyond the grasp of intellectual thought. Divorced from verbal ideation, it is difficult to point out and as difficult to enquire into. It cannot be communicated through words and [therefore] is not within the scope of the neophyte (adikarmika). Nevertheless the path is to be approached through studying scriptures (sutra) of the World-Teacher and following the personal instructions (upadesa) of one's Guru-ji."
Bodhicittabhavana by Acarya Sri Manjusrimitra