Given the hype you might be forgiven for mistaking HTML5 as the 2nd coming. But all joking aside this is a significant step for the web but what does it really offer web developers? Well this is a question that I feel is answered in HTML5 Up and Running.
First thing to point out is that this book at just under 200 pages, is not an in-depth coverage of all the new features coming with HTML5. But if you're like me and only want a quick overview to catch-up with current developments in HTML5 this could be the book for you.
I found this book written and presented in a very clear and friendly manner that made reading the book enjoyable. The author Mark Pilgrim and there is a little IE bashing but nothing over the top. While reading it is important to remember that many aspects of HTML5 are still in development and are therefore subject to change. Having said this I still think this book is useful. One criticism that I did have is I felt there was rather too much coverage of the media aspects such as audio and video, this criticism could be attributed to the type of apps that I find myself building most often.
Personally I enjoyed the coverage on Microdata and felt it gave me a nice introduction to get up and running with this feature. Other useful chapters included the new forms input types and the new tags such as <header>, <article> and <footer>. Other topics were interesting and well covered.
HTML5 is still evolving but this is a book that could help you catch up quickly but rather than just taking my word for it you can read the book online for free at: http://diveintohtml5.org/