A well presented book which in the main clearly describes the concepts involved. Perhaps some of the grammar trips itself up now and again. But in the main high marks for clarity and content. The type face, presentation and structure are also good.
Major problems start however, when you realize that the book contains almost no self contained examples that you can type up, study and experiment with. This is how most people learn. You do something, and then check the result of what you did. This is best done with short examples to keep the learning cycle short i.e. make progress and build understanding.
Most bits of code in the book are excerpts from code you must download to get any meaningful results - not just the script, but also markup and CSS. Also, some seem to depend on JQuery UI's and this is not always made clear in the book. Only when you look at the markup do you see what's called. Simply put, on their own, many code samples as printed are useless in terms of taking actions to see results. It seems you are to download the code and study that using the book. This means you do nothing!! I understand the need to use UI's and CSS, but here the learning process is reduced to passive reading. Also some of the excerpts do not match the code downloaded.
Having to create your own harness to test the scripts is in itself a useful activity, but not a reason to buy the book. Is this not what the authors should have done?
Perhaps the book is designed for front end cut and paste types who want to download working pages to paste into to produce something that works. But, if you really want to get to grips with JQuery from a programmers perspective - look elsewhere. Pity, a wasted opportunity.