HTML5 Game Dev Tutorials
I've you've had trouble wrapping your head around WebGL, the Mozilla Hack Blog has a create, very well-written introduction to the core concepts of WebGL
Kyle Nau has posted an excellent 30 minute video tutorial on HTML5 Web Audio with a razor focus on using Web Audio for simply loading and playing sounds in games and not worrying about all the other stuff, that can get pretty complex.
It's great tutorial for people who haven't yet started playing around with HTML5 Game Development as it covers a lot of the basics in detail from the ground up.
HTML5 Rocks has a in-depth article discussing the much-heralded pointer lock API and along with an overview of how to build FPS-style mouse-powered controls.
A great article on some very specific considerations for your code to make it take advantage of all the optimizations that V8 does these days.
Check out the full article on HTML5Rocks
The blog digitalerr0r has an excellent 3-part series on creating a HTML5 Game in Windows 8 that shows you the pieces you need to build a game for Windows 8 and successfully get it submitted to the Windows 8 store.
Download the HTML5 Game Starter Kit for Windows 8 and then either follow the individual links or watch the video embedded below.