"Teachings of Gurdjieff - A Pupil's Journal" by C. S. Nott

CS Nott's book is well known for the wealth of information it provides, first-hand, that could not be otherwise found in other books when first published in 1961 by Penguin Arkana.  Nott's book is divided in three parts: the first part details his first stay at the Prieure at Fonteainbleu, the middle part is an extensive commentary on Gurdjieff's "Beelzebub's tales to his grandson" as gathered from Orage's talks in New York City and the third part, and the shortest, describes the second stay of Nott and his wife at the Prieure during which the author experiences a sort of "enlightenment" which takes him to the "next octave" as expressed in the Gurdjieffian Method.

Nott's book is deeply colored with Puritanic ethical and religious references, peppered with quotes (some page-length) from "The Pilgrim's Progress" and the main protagonist Christian.  This may turn off some readers who are not familiar with the Pilgrim/Puritan/Protestant worldview, but others might find the references clear and familiar.

Nott describes himself as a physical worker, not a man of books of of philosophical inclinations.  This makes his perspective unique from those of the other contemporary pupils, many of which went on to write books about their personal experiences after Mr. Gurdjieff's death.  Nott dug a large amount of trenches around La Prieure and had his final enlightenment there after a prolonged digging spell.  Mr. G. adapted his method to suit the capabilities and preferences of the student at hand, as the main principles are the same whether approached through the purely physical, the emotional or the intellectual aspects.

There are lots of advanced concepts like "pondering" being discussed and the book has probably more value as a personal record than a teaching textbook.