PHP Manual Listing   - The manual explains and documents everything about PHP. Listed are the various formats, such as PDF, HTML and Palm. The manual is also available in about 12 different languages

PHP Manual   - Complete and hyperlinked manual documents and explains all elements of PHP. Includes FAQ section and user comments.
 
UNIX and Programming Section - Tutorials and manuals for Java and PHP.

PHParadise - PHP functions and snippets to view, study and download. All PHP functions are linked to their manual page, explaining what they do...

The manual Page: PHP - The bases of the language, how to use PHP with a MySQL database or an Oracle database, examples.
 

Manual Quick Reference - Quick reference that lists all PHP functions.

Official PHP Faq - A list of Frequently Asked Questions about PHP and their answers.