If you want to learn more about HTML, then I would suggest this tutorial:
http://www.davesite.com/webstation/html/This site is well done, and, at the end of every lesson, you get to try out what you just learned and you can see it in action! After you get a handle on HTML, you can move into CSS. There are also plenty of fun things like JavaScript and PHP that you can learn once you start getting more advanced.
The best way to learn computers is to try new things and don't be scared to mess up. A lot of people are scared to mess with their computer and they end up never knowing anything about them. The best way to learn how to fix a hard drive is to fix a hard drive, the best way to learn to install more memory is to install more memory. I also learned a lot by reading books, magazines, and web sites about how computers work. Maybe you have some computer savvy friends who could teach you more too.
Some good books:
HTML & XHTML: The Definitive Guide, Fifth Edition (I use this as a reference)
Web Design Garage (All sorts of cool web design stuff)
Some good sites:
http://www.quepublishing.com/promotion/1633#_ (This site has all sorts of videos that show you how to do various things with computers, like upgrading memory, or installing a processor)
http://www.davesite.com/webstation/css/ (This site has a good CSS tutorial)
http://www.w3schools.com (Is a reference site for all sorts of web design stuff.)
http://computer.howstuffworks.com/ (This site is one of my favorites. It tells how all kinds of computer related things work. Definately check it out.)
Another thing about learning computers - technology changes so fast, you will never learn everything there is to know ^__~. There is always something new out there, so don't ever get frusterated. Keep learning, keep trying new things. Send me a PM or instant message me if you ever need any help.