The Buddhist Path - A Practical Guide From the Nyingma Tradition of Tibetan Buddhism — by Palden Sherab and Tsewang Dongyal
Explanations and methods that reveal how the mind functions and what its essence is.
Gampopa - the Monk and the Yogi · His Life and Teachings — by Trungram Gyaltrul Rinpoche
In addition to a bibliography, appendices include a map and a table of place names related to Gampopa and tables summarizing the events in his life.
Generating the Deity — by Gyatrul Rinpoche
This work offers a detailed presentation of the generation stage practice of tantric deity yoga. These are step-by-step teachings on the genereation stage practices of deity yoga as they were practiced in Tibet.
A Lamp to Illuminate the Five Stages · Teachings on Guhyasamaja Tantra — by Tsongkhapa - translated by Gavin Kilty (Library of Tibetan Classics - Volume 15)
Covers the subtle human physiology of channels and winds along with the process of dying, bardo and rebirth.
The Life of Padmasambhava — by Taranatha
Biography of Padmasambhava - the famed master from Oddiyana who introduced Tantric Buddhism in Tibet in the eighth century.
Sublime Path to Kechara Paradise - Vajrayogini's Eleven Yogas of Generation Stage Practice as Revealed by the Glorious Naropa — Commentary by Sermey Khensur Lobsang Tharchin
Teachings of Tibetan Yoga — translated by Garma C.C. Chang
This is one of those rare books that goes into how to practice the inner yogas, including tummo and the other yogas of Naropa.
The Jewel Treasury of Advice - A Hundred Teachings From the Heart - The Wisdom of Drikung Bhande Dharmaradza
The author maps out, in verse, the entire structure of the Buddhist path according to both sutra and tantra.
Ornament of Stainless Light - An Exposition of the Kalacakra Tantra — by Khedrup Norsang Gyatso (Library of Tibetan Classic - volume 14)
The Kalacakra texts present an amazingly detailed theory of cosmology and astronomy, especially about the movements of the various celestial bodies.