The problem with the author is that she is having a real problem identifying her target group, you simply can't write a book that is good for total beginners to experts in the same time, it's an impossible mission imo and the case of this book it was a total failure. The author to write a book for everyone but she lost everyone.
Since the start, it was obvious for me that the book is not for experienced developers but my problem was that I thought it will be even worse for beginners, so who is it targeting? For beginners, there is a small chapter called the Basics, this is the basics of HTML (HTML4 in my opinion) and CSS and Javascript, all scrummed in 18 pages with half of them are pictures (and ugly tables for code samples). After that, it jumps straight to using canvas and the drawing api. I can't imagine how is this helpful for a complete beginner.
Another issue for beginners is the code quality, I think that teaching bad habits and design for beginners is just awful and the code samples in here are definitely not top-quality. To make it worse, the author tries hard to re-invent the wheel when it comes to terminology, like scripting languages, compiled languages, objects etc... she tries to explain in a way that she thinks it's simple, I can not say for sure how easy this makes it for beginners but a big part of any serious coding exercise is convention and patterns so I think that beginners will have an easier time speaking the language and terminology that everyone around them will be speaking.
For an experienced reader, who knows some HTML and javascript, there is no real mention of what's new in HTML5, so you will not learn about HTML5. You will - supposedly - learn about the drawing api and canvas, only that. And don't be put off by that, because this api is definitely worth a book by its own, but this is just not the right book.
To top it all, the killer for this book in my view is the very bad layout, using tables for code sample with code on the left and comments on the right, very ugly, very unreadable and ironically enough using TABLES for presentation in a book about HTML5.
This is the first review I write on Amazon and the reason is I got deceived by the two positive reviews the book had at the start, and a colleague of mine also bought it for the same reason so I felt give my honest opinion then you decide.