Cross Browser Helper

Html 5 Validator (en)

http://html5.validator.nu/

Html5 Browser capability test (en)

http://html5test.com/

Html readyness – fancy browser comparison (en)

http://html5readiness.com/

Modernizr – Cross-Browser Html5 & CSS3 Support (en)

http://www.modernizr.com/

Html5Shiv – Html5 for IE (en)

http://code.google.com/p/html5shiv/

IE-7 js – Standard complient IE 7 (en)

http://code.google.com/p/ie7-js/

Html 5 CSS-Reset (en)

http://html5reset.org/
http://html5doctor.com/html-5-reset-stylesheet/

HTML 5 Boilerplate – Best Practices, Scripts und Server-Konfigurationen

http://html5boilerplate.com/ (en)
http://de.html5boilerplate.com/ (de)

Audio/Video

Html 5 Audio and Video – What you must know (en)

http://net.tutsplus.com/tutorials/html-css-techniques/html5-audio-and-video-what-you-must-know/

Video accessiblity (en)

http://wearehugh.com/public/2010/08/html5-video-accessibility/Your text to link…

Canvas

Reference Guide (de)

http://canvas.quaese.de/

Canvas beginners guides (en)

http://www.brighthub.com/internet/web-development/articles/38744.aspx
http://www.visitmix.com/Articles/Translating-CANVAS-with-HTML5

Canvas demos & tutorials (en)

http://www.canvasdemos.com/

Cookbooks & Tutorials

Html 5 cheatsheet

http://websitesetup.org/html5-cheat-sheet/

WHATWG Weblog (en)

http://blog.whatwg.org/

Html 5 laboratory (en)

http://www.html5laboratory.com/

Dive into Html 5 (en)

http://diveintohtml5.org/

Html5 Playground (en)

http://www.html5rocks.com/

Tag reference (en)

http://www.w3schools.com/html5/html5_reference.asp

Fancy tag reference (en)

http://joshduck.com/periodic-table.html

Html5 Techniques – Ultimate collection of tutorials (en)

http://www.tutoriallounge.com/2010/11/html5-techniques-ultimate-collection-of-tutorials/

Useful html 5 code snippets (en)

http://www.onextrapixel.com/2010/11/15/useful-html5-code-snippets-you-can-use-today/

Geolocation using the Google API (en)

http://papermashup.com/html5-geo-location-using-the-google-api/

Fun with html5 forms

http://thinkvitamin.com/code/fun-with-html5-forms/

Blog-Artikel & andere Quellen

Webkrauts Artikel zum Thema (de)

http://www.webkrauts.de/category/html5-einfuehrung/

What beautiful Html5 code looks like (en)

http://css-tricks.com/what-beautiful-html-code-looks-like/

48 Flash killing HTML 5 demos (en)

http://www.hongkiat.com/blog/48-excellent-html5-demos/

HTML 5 facts & myths (en)

http://www.smashingmagazine.com/2010/09/23/html5-the-facts-and-the-myths/

Learning to love html 5 (en)

http://www.smashingmagazine.com/2010/11/10/learning-to-love-html5/

Designing a html 5 layout from scratch (en)

http://www.smashingmagazine.com/2009/08/04/designing-a-html-5-layout-from-scratch/