This is an old thread, I know, but I just wanted to say that I bought a book by
www.w3schools.com to learn both HTML and CSS and it was enormously helpful. Also, someone mentioned lynda.com, which is another great site. Check with your library - mine has an agreement with lynda.com and I get to take as many classes on that site as I want to as part of my library membership, so I don't have to pay for the classes. I'm not sure if that's standard with libraries, so definitely check with your local branch!