http://www.initializr.com/
Wicked site to generate HTML5 boilerplates or starting points from which to design stuff. includes bootstrap, Google Analytics, and loads more stuff. Very, very useful.
http://www.flaminglunchbox.net/curvy
Awesome game built in HTML5 from an Android version. Very cool.
http://diveintohtml5.org/storage.html
A really easy to understand intro to html5 and other stuff. Very handy, beautifully written, elegantly presented, a joy of a web page.
http://developers.whatwg.org/offline.html#offline
Very useful article on offline web apps using HTML5 cache manifests.
https://github.com/PicNet/picnet_closure_repo/tree/master/src/pn/data
Local data store abstraction layer in javascript, tries IndexDB, WebSQL, Google Gears, then localSotrage in that order. Very useful for cross browser data storage.