Padraic Brady has released chapter one and chapter two of his "Surviving the Deep End" Zend Framework book:

As many of you know, the book is available online without charge. [...] Let me know your thoughts, and post any general comments or questions on the book or website here. I'll be adding a general end-of-page comment system to the mix during the next day or two so posting general comments here is a temporary stopgap.

The first chapter is just an introduction looking at what the book will cover and what the framework's all about. Chapter two gets a bit more in depth, looking at the architecture of the Zend Framework and details things like routing and how it implements MVC.