Articles on the philosophy of the guardian warrior:

"The Native Commandments" (Core of the guardian way) by Tamarack Song

"The Way of the Warrior" (An excerpt introduction to the guardian way from
the book "Jourey to the Ancestral Self") by Tamarck Song

"Who is the Guardian Warrior?" (A draft for the introduction to an upcoming
book on the guardian way) by Tamarack Song

"The Way of the Wolf: Guardian Awareness" by Tamarack Song

"The Line of Sight: How the Guardian Serves" by Tamarack Song

"How Peace Drum came to the People" As told by Tamarack Song

"Guardian Warrior Stories" as told by Various Authors

"The Art of Nothing" by Thomas J. Elpel
Books which speak to the philosophy of the guardian warrior:

"Original Wisdom: Stories of an Ancient Way of Knowing" by Robert Wolff

"Journey to the Ancestral Self" by Tamarack Song

"Old Indian Days" by Charles Eastman (Ohiyesa)

"Follow The Warrior's Path; Life Story of Ohiyesa, Better Known as Dr.
Eastman" by Mary Rubeck Benson

"Lame Deer, Seeker of Visions" by John (Fire) Lame Deer & Richard Erodes

"Ishi in Two Worlds; A Biography of the Last Wild Indian in North
America" and "Ishi, Last of His Tribe" by Theodora Kroeber

"The Forest People; A Study of the Pygmies of the Congo" by Colin M.
Turnbull

"Limited Wants, Unlimited Means; A Reader on Hunter Gatherer
Economics and the Environment" edited by John Gowdy

"Wandering God; A Study in Nomadic Spirituality" by Morris Berman

Books from the martial arts, which (in spite of differences between martial &
guardian ways) still capture an important essense of the guardian path:

"Ninjitsu, History & Tradition" by Dr. Masaaki Hatsumi

"The Way of the River, Adventures and Meditations of a Woman Martial
Artist" by B K Loren

"On the Warrior's Path, Philosophy, Fighting, and Martial Arts Mythology"
by Daniele Bolelli

"The Zen Teachings of Bodhidharma" translated by Red Pine

"Scholar Warrior; An Inroduction to the Tao in Everyday Life" and "The
Chronicles of Tao" by Deng Ming-Dao

"Zen and Japanese Culture" by Daisetz T. Suzuki

"Bushido, The Way of the Samurai" based on the Hagakure by Tsunetomo
Yamamoto, edited by Justin F. Stone, from the original translation by
Minoru Tanaka

"The Lone Samurai, the Life of Miyamoto Musashi" by William Scott Wilson

Resources which help clarify why the guardian way is not the way of military
service:

"War is a Racket" by Smedley Butler (USMC Major General, Retired)

"On Killing" by Dave Grossman (former Lt Colonel, U.S. Army Rangers)

"The Ground Truth" (Video dccumentary, Iraq war veterans tell their story)