On the other hand, you need to know your HTML and CSS selectors, as the book only says that jQuery uses CSS selectors to select elements.
The examples in the book are well explained and commented!
The book starts off with an introductory chapter about jQuery, what it is, why the author chose it over other JS libraries, what projects use jQuery and so on...
The “Quick tricks” chapter shows some really quick but useful tricks, such as dynamic select boxes, contextual help or inline editing. OK, you may have all done this before, but it's a good starting point for getting to know jQuery.
From chapter 3 to chapter 9, the author shows how to do things like validating forms, creating an event calendar, managing files and folders from the browser, rotating, cropping, resizing images (with ImageMagick!) also from the browser or making lists sortable by dragging and dropping items. Of course, no one wants to reinvent the wheel, so all the examples are using plugins – either from the jQuery UI collection or “standalone” plugins that are “too specific” to be in the said collection.
My personal favorite chapter is the “Data tables” chapter, which shows how to present and use table data on your website by adding sort, filter and pagination functionality to your table. The example shown uses a table with over 2 million rows, which is worth mentioning, cause this way we know that it'll work on a large dataset also.
In conclusion, if you're a PHP dev wanting to “spice up” your apps, this book will most likely worth the money spent.