I've posted a pre-release, full version PDF of a new HTML book/online combination. free until printed. It's for serious learners. Starts with doctype. Chapter 5 recommends forums, this one included, for learning. http://martinrinehart.com/frontend-engineering/knowits/v1/print.html Feedback, please! TIA.
There really isn't any such thing as HTML5 yet. W3C has divided work on projects such as HTML into subprojects and the status of subprojects is tracked individually. Their statuses range from barely started to near final, waiting for the last dot on the last "i". When enough of the subprojects get to their late stage, they will be bundled and officially named "HTML5". The others will be the ones people call "HTML6" (or 7, or 8 or abandoned). So you really want to start studying a year or two ago. Like graphics? Start on <canvas>. Need file I/O? Try the File API. Like movies and music? ... You get the idea? HTML is pretty small, today. HTML5 is huge. Don't wait.