The ExtJS book I got was published by Packt Publishing. It is called "Learning ExtJS 3.2". I consider myself experienced ExtJS developer but there are always more experienced developers and the book was written by several of them.
This book is written by several active participants of ExtJS forums: Shea Frederick, Colin Ramsay, Steve 'Cutter' Blades and Nigel White. It contains seventeen chapters and 394 pages, which makes the book 2 centimeters thick.
When I looked through the table of contents, I realized that it is one of those rare books that suits all kind of readers: from beginners to advanced. The book starts from "Getting ExtJS" chapter. It discusses why ExtJS is different, how to get it, where to put it, etc. While this may seem like a chapter for beginners, I read it with interest and found several advices I will use in my next project. The opening chapter also tells what to do if the developer sees error messages. This is another advantage of the book: it is highly practical.
Next chapters describe how to use ExtJS. Here is what is covered: getting elements, creating and using forms, working with menus and toolbars, displaying and editing data with grids, using layouts for components (you can quickly rearrange objects by just applying another layout), creating tree controls, using windows and dialogs. There are also chapters about charts, effects and drag-and-drop. In addition there is a chapter about extending ExtJS. This area is probably one of the most difficult for programmers because this is not what the developer can find in the ExtJS package. The topic about extending ExtJS takes 38 pages, so it is really well covered.
Another interesting topic discussed in the book is data transfer between the browser and the server. There are traditional ways (such as AJAX) but ExtJS and the book go further discussing remote method invocation from the client on the server using ExtDirect. ExtDirect is a hot topic in the ExtJS community because it greatly simplifies communication between the client and the server. Thus the developer can save development time.
The final chapter in the book talks about useful additions to ExtJS such as HTML editor, state management on the browser side, using AIR, etc. It also describes several community extensions to ExtJS (such as TinyMCE and SwfUploadPanel) and how to use them.
The book contains a lot of examples, so the reader can learn through them. One side note here (and a recommandation to Packt editors): I found that spacing in the examples could be smaller to avoid line wraps. Reading of examples would be easier if spacing is reduced. Truly speaking, this is the only bad thing I can tell about the book.
Despite being experienced in ExtJS and using it since version 1.x, I found a lot of good tips in this book. It is really useful and now lives on the shelf among good programming books. So if you need a good learning resource about ExtJS, I can definitely recommend "Learning ExtJS 3.2" from Packt Publishing.
P.S. Current version of ExtJS at the time of writing of this review is 3.3.1. That does not make the book obsolete at all.