Where can I find resources to learn HTML5?

A working knowledge of HTML 5 is going to be useful for a wider audience than the traditional users of HTML as it will have a role in apps development in Windows 8 and elsewhere. I have gathered together some resources I have found useful.

Samples  and Demos

Sites that demonstrate working examples of HTML and its features.

Books and on line courses

Specific Aspects of HTML5

Drag and drop

Geolocation

explanatory articles:

Transitions

 Web fonts

Shiv

Code Checking

Modernizer

HTML 5 Boilerplate projects

Other technologies if HTML 5 not supported

Other Sites

APIs

References

Standards

 Accessibility