Robert J. Lang. The Complete Book of Origami: step-by-step instructions in over 1000 diagrams. Dover Publications, Mineola, NY. Copyright 1988 by Robert J. Lang. ISBN 0-486-25837-8 (pbk.)
Pages 1–30 are an excellent introduction to most of these skills. Each of these 13 models is designed to let you practice one skill several times. Unfortunately, the remaining 24 models leave out lots of pre-creases.
Pages 1–88 explain how the crease patterns of the classic bases are related to each other, how they are examples of fractal design, and how it is possible to generate arbitrarily complex origami designs.
This book shows how crease patterns and folding techniques are related to the large-scale structure of a model. It also shows how closed-unsinking was derived, using Lang's TreeMaker software for prototyping arbitrarily complex origami designs.