For over two decades, this comprehensive manual has been the standard introduction and complete reference for writing articles and books containing mathematical formulas. If the reader requires a streamlined approach to learning LaTeX for composing everyday documents, Grätzer¿s © 2014 Practical LaTeX may also be a good choice.
In this carefully revised fifth edition, the Short Course has been brought up to date and reflects a modern and practical approach to LaTeX usage. New chapters have been added on illustrations and how to use LaTeX on an iPad.
Key features:An example-based, visual approach and a gentle introduction with the Short Course
A detailed exposition of multiline math formulas with a Visual Guide
A unified approach to TeX, LaTeX, and the AMS enhancements
A quick introduction to creating presentations with formulas

From earlier reviews:
Grätzer¿s book is a solution.
¿European Mathematical Society Newsletter
There are several LaTeX guides, but this one wins hands down for the elegance of its approach and breadth of coverage.
¿[...], Best of 2000, Editor¿s choice
A novice reader will be able to learn the most essential features of LaTeX sufficient to begin typesetting papers within a few hours of time¿ An experienced TeX user, on the other hand, will find a systematic and detailed discussion of LaTeX fea

tures.

¿Report on Mathematical Physics
A very helpful and useful tool for all scientists and engineers. ¿Review of Astronomical Tools