But if you want to be an html monkey for real, here are some basics. But it's important anyway. On the internet, people like standards.
Standards are how software talks to eachother.
HTML is a standard so that people can mark up pages without worrying about what software others use. To make sure you are marking up properly use an html validator such as the one at w3c. If you aren't that zealous then at least check it in two browsers, if not three or four. Information wants to be free When you make a page or write a javascript, people will be able to see your source. Deal with it.