On the TutsPlus.com site, they've posted a tutorial for those wanting to get started with object-oriented programming (OOP) in PHP. In this introductory article they cover the basics of objects, classes and several over OOP-related topics.
In this article, we're going to explore the basics of object-oriented programming in PHP. We'll start with an introduction to classes and objects, and we'll discuss a couple of advanced concepts like inheritance and polymorphism in the latter half of this article.
The tutorial starts with the basics, explaining some of the key terms involved in OOP and how they can be manipulated. From there they include code examples of classes, making instances of them as objects and accessing properties and methods. With those basics out of the way, they move on to more advanced topics: encapsulation, inheritance and the basics of polymorphism.