HTML5 is a huge joke. Its not going to be finished until 2022, so until then, anything in it could change. HTML5 is only a beta.
As for CSS3, instead of being a single specification, its going to be modulized. There is some color module complete already.
Learning CSS2 is a huge joke also. The official documentation is burred, deep deep in the W3C's website and its written by and for computer losers that have all the time in the world on their hands, in other words, its useless for every day people - which is probably who you are.
There are 3rd party resources such as w3schools, but they usually encourage non compliant hacks like <if IE> These target browsers, rather standards... and this is how the noobies code, so you don't want to go that way.
W3schools however can be useful for understand the flow of how stuff works.
My opinion is just look at example code and try and learn off it enough until you understand how the flow works, then jump onto W3C's HTML page and look at the elements and attributes. As for CSS 3, don't bother with the W3C's site (unless your a womanless loser with all the time in the world).
There is an official validator for HTML at validator.w3.org which will tell you if your code is valid.
There is also one for CSS2. Look it up.
Best of luck!
Last edited by FlashDance; 11-10-2011 at 07:23 AM..