A List Apart is a must-know website for any developer, covering everything from presentation to the markup behind the page. This article from A List Apart by J. David Eisenberg goes through suggestions to get your website HTML5 ready. He talks about XHTML5, regular expressions and the canvas element with SVG.
Josh Duck has created this beautiful periodic table for HTML5. Though you don’t have to memorize all the elements of the table, it links each element to a resource which will tell you more such as the W3 documentation. Also, by inputting a website into the ‘How are they used?’ It will breakdown the website into elements used, immensely useful for any web developer. It also is color-coded by the type of element, for example by tabular data.
This is a very cool website with many tutorials sorted by each new category of the HTML5 specification. Visit the code playground with a HTML5-ready browser (I hope you’ve ready done that) for some examples with source code. The website was created by employees at Google, who also work on Chrome development.
This websites shows the power of HTML5 in some simple demos. It helpfully sticks to using one or two new technologies in each example and source code is available for all of the examples. It also tells you what each browser supports and all code is licensed under Creative Commons Attribution-ShareAlike 2.0 (UK).