While browsing the web, I’ve found this book on PHP, called Survive the deep end. I’ve thoroughly read some chapters and I can honestly say that I’m impressed. This is a very good book, one of the best books I’ve read lately. It’s not just another “copy & paste this script and it should do the trick” book. It features advanced concepts that are actually useful, it promotes best practices and you can easily see that the author is a seasoned PHP developer, willing to share his knowledge with world. The book is authored by Pádraic Brady, a developer Ireland and active contributor to the Zend Framework code base. He also maintains a blog at blog.astrumfutura.com – another good read, as he has some interesting stuff posted there.
Final recommendation: even if you’re not a Zend Framework user, you can still read it and learn more about things how to design a MVC application and apply that knowledge to your framework of choice. Survive the deep end.