The Definitive Guide to HTML5 provides the breadth of information you'll need to start creating the next generation of HTML5 websites. It covers all the base knowledge required for standards-compliant, semantic, modern website creation. It also covers the full HTML5 ecosystem and the associated APIs that complement the core HTML5 language. The Definitive Guide to HTML5 begins by tackling the basics of HTML5, ensuring that you know best practices and key uses of all of the important elements, including those new to HTML5. This section also covers extended usage of CSS3, JavaScript, and DOM manipulation, making you proficient in all core aspects of modern website creation. The final part of the book covers the associated W3C APIs that surround the HTML5 specification. You will achieve a thorough working knowledge of the Geolocation API, web storage, creating offline applications, and the new drag and drop functionality. The Definitive Guide to HTML5 also dives into the key media enhancements of HTML5 and its surrounding Canvas, video and audio.
The title of this book says 'Definite Guide'. I'd agree with the first part, but not the second. In essence is it is a HTML5/CSS3 reference book with (mostly) short&sweet demonstrations. In some chapters the author goes a bit deeper due to the complexity of the topic (for example in chapters about Ajax), but even there the penetration is really skin deep. Nevertheless, the book is well-structured, accessible and covers all aspects of HTML5/CSS3 along with necessary Javascript basics.
The problem I have with books like this one is basically that I'm having hard time deciding what it really is good for. The reference part is just as easily found online - go to www.w3.org and you'll get pretty much the same information from the horse's mouth. The demonstration part is nice to have, but not very useful for educational purposes - sure enough, newbies will understand what each 'piece' does on its own, but it won't help them with the real challenge of putting them together into 'whole picture' of an application. On the other hand, people with previous experience will probably already know this basic stuff. The real value of this book (for me at least) consists of author's personal comments about different aspects of HTML5 which are based on his personal experience and those comments are spread throughout the book like golden nuggets and to be honest, are just as rare.
If you're just starting with HTML5 development, I'd suggest you'll look elsewhere. If you're looking for a complete reference book with some good advice from an experienced guy added as a bonus, then this volume could be worth picking up.
This book provides clear-headed, no-nonsense coverage of HTML 5, CSS 3, and JavaScript with a depth and extent that make it very helpful for the prospective web developer. There are code examples of practically everything that the book touches on. This is no mean feat considering how much material is covered.
If the book has a weakness, it is probably that it is four years old (at least, the edition I read was). The result of that is that its guidance with respect to the status of the standards' implementation by browser publishers is getting stale. Fortunately there are sites like caniuse.com which help getting the latest information on this.
I should be honest and point out that much of the material in this book is available online for free, but it is not bound under a single cover and you have to go and find that material yourself (often without decent usage examples). There is something to be said for having it all one place.