When I am looking for a reliable source of information on HTML and CSS, the number one source I turn to is W3Schools. I was under the impression that it was affiliated with the W3C, the nonprofit consortium that is responsible for web standards, but that was actually a mistaken impression. W3Schools is actually the creation of a Norwegian web development firm called Refsnes Data. Now that I know this, I will no longer treat their answers as authoritative. Nevertheless, their information is based on current web standards and regularly updated.
For insights into WYSIWIG or Adobe Suite problems, I do a google search, and often what pops up is Stack Exchange, usually UX, Graphic Design, or Webmaster’s stack exchange. This is a site where questions and answers are up-voted by the community. I only just recently registered myself, because I finally feel confident enough to participate in the community.
Finally, Adobe itself has tutorials and forums that are sometimes helpful. I tend to use stack exchange first, because the up-voting mechanic moves the most helpful answers to the top, but the official forums sometimes have answers that aren’t on stack exchange. Having official answers and the ability to get the company’s attention is helpful, though of course the official way is not always the best way. Sometimes users figure out how to do something with a piece of software the developers never intended.