This list is comprised of HTML5 books that are going to be released in the second half of 2013 and also includes 2 books that will be hitting the shelves in 2014. They cover a wide range of skill levels.
Treehouse, an online learning resource is embracing HTML5. They offer an extensive library of step-by-step video courses and training exercises. They also just released an HTML5 book.
The eBook HTML5 Security is a must read for all serious developers especially since its priced under $5.