Of all the PHP books in my library, I use this one the most. Warning: do not attempt this book if you have no concept of object-oriented programming (OOP). I would try understanding chapters 1 & 2 of "The Object-Oriented Thought Process" (Weisfeld) or some other OOP for beginners book prior to tackling this one. However, this book is amazing if you have a preliminary grasp of OOP. Basically each chapter gives instructions on how to harness and customize a different built-in PHP class (for example, chpt3 the DateTime class for displaying/calculating dates, chpt6 the SimpleXMLElement class for creating/parsing XML documents, etcetera). As a bonus, chapter 7 offers an introduction to the SPL (Standard PHP Library), a collection of classes built into PHP for solving standard problems.