I'm so happy no announce my new Ext JS 4 book called Mastering Ext JS, published by Packt Publishing!
The book is not finished yet, but the RAW (read as we write) version is already available.
In this book I demonstrate how to create a complete Ext JS application, from the directory structure to bundling for production.
Some things you can find on the book: dynamic menus, open a tab dynamically, master-detail information, charts, export to image, pdf and excel, MVC, reuse of code, abstract classes, how to use Ext.ComponentQuery, general tips and tricks that can help a developer's life e much more.
I hope you enjoy it, was written with love to the Sencha community!