This is a classic introductory text in which Tezuka Osamu expounds the basics of drawing, using a simple example and also explaining about the different tools for Manga drawing and how they are used. There are many instances of professional Manga artists who have said that they learned how to draw Manga with this text.
"Tezuka Osamu ~ How to Draw Manga," Kobunsha Kappa Homes, 1977.