"Words of my Perfect Teacher", Mipham Rinpoche
Neither of these are exclusively Nyingma but they certainly reflect a Nyingma flavor and view overall.
LIGHT OF FEARLESS INDESTRUCTIBLE WISDOM: The Life and Legacy of His Holiness Dudjom Rinpoche
(although not an overview of the Nyingma school in general)
THE BUDDHIST PATH: A Practical Guide from the Nyingma Tradition of Tibetan Buddhism
(both of these are by the Khenpo Brothers)
THE LOTUS-BORN: The Life Story of Padmasamhava, by Yeshe Tsogyal - I gave this text away some time ago but if it's the book I'm thinking of this is the story of Padmasambhava bringing Buddhism to Tibet and is thus the foundational story of the Nyingma.
I have not seen this but NYINGMAPA: Bodhgaya to Tsopema DVD, by HH Penor Rinpoche. The Snow Lion blurb says:
These teachings include wonderfully vivid footage from a pilgrimage from Bodhgaya to Tsopema, the sacred lake of Padmasambhava. Included are: Nyinmapa Grant Cerermony; several teachings by Penor Rinpoche; introductions to Bodhgaya and Tsopema; the story of Guru Rinpoche subjugating the king of Zahor; the footprints of Padmasambhava; and more. Comes with full-color booklet.