Image may be NSFW.
Clik here to view.I've been thinking a lot about HTML5 and how I can get started with it early on and hopefully stay ahead of the curb. I found a site/book that does a great job of laying things out - diveintohtml5.org.
I haven't gotten too deep into it, but just scraping the surface of a few chapters has already taught me some interesting facts about HTML5.
I also found a couple of other tools that would come in handy for web development (and design):
http://html-ipsum.com/ - Provides quick access to lorem ipsum text for quickly filling in templates.
http://jsfiddle.net/ - An interactive web design and development playground.