Object Oriented Programming in PHP: The way to large PHP projects is a good article & others st:
http://www.phpcomplete.com/tutorials.ph ... tionDesign
Patterns:
http://www.phppatterns.com. Patterns might not be too useful at first: I think you maybe need to muck in and write some OOP scripts before patterns really start to make sense. The factory pattern is maybe an easy one to start on - and factory recall which feels like standing between two mirrors.
eclipse
http://www.students.cs.uu.nl/people/voo ... /index.php is a highly regarded example of OOP in php. Small, efficient classes are the way to go. Check out the read me for important information about how to use references with classes.
Also, have a read through the advanced forum where you'll find a few OOP topics.
Php sometimes gets criticised as not being a good OOP language: in fact, I suspect that - as in other areas - it's built-in flexibility makes it one of the best.