Best practice und jede Menge weiterer Tipps/Links etc. unter:
http://html5boilerplate.com/
http://net.tutsplus.com/tutorials/html-css-techniques/the-official-guide-to-html5-boilerplate/
Ne ganze Reihe interessanter Artikel hier:
http://net.tutsplus.com/sessions/html5-and-you/
HTML5 Showcases:
http://ehabaref.com/2011/02/40-beautiful-examples-of-html5-website-showcase/