http://www.e-learningcenter.com/free.htm

and you can locate many others by pasting the following bolded text (including quotes) into a Google Search --
"web design" with "free online class"

Web Design includes much more than just HTML though. You might consider going to this link and downloading WebPlus 6.0 - Web Site Design & Publishing as well as DrawPlus and PhotoPlus and even PagePlus would be handy. Their documentation could get you started too.
www.freeserifsoftware.com/default.asp