You are not going to get very far programming HTML5 unless you already program in JavaScript. If you don't then Head First HTML5 Programming (O'Reilly) by Eric Freeman and Elisabeth Robson provides an introduction to JavaScript programming in the context of HTML5. As long as you like the distinctive style of presentation of Head First books, which is characterized by lots of attempts at humor, illustrations, quizzes, discussions and so on, this can be recommended as
quite a good outline of what modern browser based JavaScript programming is like.

Pick of the Shelf

To date, the only HTML book that has been awarded the 5-star accolade is HTML5: The Missing Manual (O'Reilly) and this book by Matthew MacDonald came out in 2010 and so benefited from the fact that at the time HTML5 was indeed new and needed documentation.

At that time we faced the big big problem of browser compatibility,  and to a great extent we still do. This particular book aims to make it all much clearer and in the main it succeeds.

This is a very straightforward book that starts by going over the history of HTML through XHTML and the problems that eventually resulted in HTML5. It explains the design philosophy and then takes you for a brief walk through creating a very simple HTML5 page. The book then devotes two chapters to the central innovation of HTML5 - semantic markup.

Part 2 of the book looks using at the new functional tags in HTML5 and at what we can still consider the star of HTML5 - the Canvas element. This covers not only basic Canvas use, but also more advanced general topics such as animation and hit testing and for this you need to have a good understanding of JavaScript. If you need to get up to speed with JavaScript there's an appendix that covers it - but it won't get up to the standard that the book expects.

Part Three of the book covers the various APIs introduced along with HTML5 to extend the way that you can use JavaScript to write web apps that behave more like desktop apps. It goes into web storage, offline applications, messaging and web socket,  and geolocation and web workers. This is at much more advanced than the earlier chapters.

The review, which was posted in September 2011 concludes:

If I had to pick a single HTML5 book to read, this would be it. It is an easy read and it gives you a clear idea of what is and is not in the current HTML5 specification. Recommended.

The only problem I have with repeating this recommendation is that now it is probably time for the 2nd edition!

Why so few recommendations?

After trawling through all the reviews we have done on HTML titles for developers, including books in other categories such as mobile and games, the conclusion is that there is a real dearth of titles to recommend.

But perhaps the problem lies not with the authors and editors of the books but with HTML5 itself and the premise that it is a suitable development environment. HTML is a markup language and there's not a lot you can do with it on its own. Indeed David Conrad's review of HTML5: Designing Rich Internet Applications (Focal Press, 2010) which he rated as a 3 on the grounds that "certainly isn't about creating Rich Internet Applications" made the point "most of the new features in HTML5 are fairly simple and easy to understand - you don't really need a book"

When you move on and consider HTML5 as a way to create web apps then you very quickly discover that HTML5 as markup is a tiny part of the solution and hence a tiny part of the problem. The real issues are in the CSS and the JavaScript - but of course these aren't hot buzz words so books dealing with the problem are slower to materialize.