On the KillerPHP blog, Stefan Mischook introduces a PDF that he's created to help beginners get a grasp on working with objects in PHP:

I've written up a short (2 pages,) document that goes over some of the very basics of object oriented programming - it should take you all of 5 minutes to read. I wrote this as the preamble to my next video on object oriented PHP where we will actually create living breathing PHP objects.

The post includes an excerpt from the PDF that talks about how objects are created.