the ultimate textbook
Written by Debra Cameron et al
Written in English
Learning GNU emacs is the best textbook available teaching emacs - the best editor there is. Both beginners and experienced emacs users will find this book useful. Here you get everything from the simple introduction to emacs to more advanced topics.
The book is far from covering all of the topics regarding emacs, but such a book would be larger than the worlds largest book. Still you learn enough that after reading this book you can call yourself an advanced emacs user. It's important to read the introduction as it gives a good description of which chapters to skip depending upon how much experience you have. This is a book you should always have on your desk as a work of reference. It's actually quite often easier to find information in the book than online. Together with "GNU Emacs Pocket Reference" this book is the ultimate textbook about emacs. Buy them both and make space for them on your desk. You will not regret it.