Free PHP Books and Sample Chapters

PHP Best Practices
Either a short book or a series of articles, this text is not a tutorial and is meant to be useful to people who already know PHP. Since PHP offers multiple ways to do the same thing -- connect to a database for example -- this is a guide suggesting the best direction to take when facing such situations.

PHP 5 Power Programming
In this book, PHP 5's co-creator and two leading PHP developers show you how to make the most of PHP 5's industrial-strength enhancements in any project - no matter how large or complex. (Use the download as pdf link under the synopsis).

PHP Essentials
The book is intended to cover all aspects of PHP. It begins by covering the history of PHP before providing a high level overview of how PHP works and why it is so useful to web developers. It then moves on to cover each area of PHP in detail, from the basics of the scripting language through to object oriented programming, file and filesystem handling and MySQL and SQLite database access.

Practical PHP Programming
This is an unpublished book on PHP. This book assumes no PHP programming skill at all - you will be taught from scratch in that respect. It appears to be quite comprehensive and can be navigated online in tutorial fashion, so it serves as an online php book or php tutorial.

The Definitive Guide to symfony
This book introduces you to symfony, the leading framework for PHP developers, showing you how to wield its many features to develop web applications faster and more efficiently, even if you only know a bit of PHP.

PHP Reference: Beginner to Intermediate PHP5
You can download this book as an epub or pdf file.

Programming : PHP at wikibooks
This is an open content php textbook from wikibooks. It covers the basic of the PHP language as well as some advanced concepts such as OOP and templating.

Practical Php Testing
This book is aimed to php developers and features the articles from the Practical php testing series, while the other half of it is composed by new contents. The book comes for free and is licensed under Creative Commons.

PHP Session Management With Cookies
Book excerpt at O'Reilly.

The PHP Cookbook
A collection of problems, solutions, and practical examples for PHP programmers. It was written in 2003 and is a tad out of date, but might be useful to someone, so I am letting the link stay for now.