Fiction Factory

William Wallace Cook was a famously prolific writer, turning out so much pulp fiction that he was called "the man who deforested Canada."
Best remembered today for his plot-generation book, Plotto, Cook also chronicled his first two decades as a high-volume pulp writer, The Fiction Factory. He tells how he got started as a fiction writer and the ups and downs of freelancing at the turn of the last century.
In addition to being fascinating reading in its own right, the book shows how much harder writing used to be. Cook was not only an early adopter of the typewriter, gratefully abandoning his fountain pen, but also of the index-card-based filing system, which made his precious collection of background material (newspaper and magazine clippings) far more accessible.
There's no better chronicle of an author writing quickly and with increasing ease, year after year.