In general, my first stop for HTML, Javascript or DOM information is the MDC Doc Center from the Mozilla Developer Network. It is occasionally Firefox/Gecko-specific, but is in general a good first stop.
- HTML doc center
- Javascript doc center
- DOM doc center
Personally, I find the HTML spec (and even more the DOM spec) far to hard to take in quickly or to use as a quick reference. MDC is great for that.
