I learn when i started my very first site which was for the Nintendo Dsi Browser i currently dont have my own pc so ive stop it for a while
I learned to code from a buddy of mine. He use to teach me over the phone in his spare time. It was great because he is an amazing coder and could recite an entire php based code in his head straight to me over the phone while he was buying something at the store. After that I sort of just started studying code on my own. I picked up a couple of books at my college and studied them for endless hours.
Although I went to college to study web development most of the techniques I use today are self taught mainly by using onlline tutorials. I havent been on for a while but I found pixel2life.com to be a great learning resource.
I took an online college course for html and learned javascript, actionscript, asp, from books and practice.
I started by just doing some playing around myself and then I started reading and couple books and websites and here I am today. Best website to learn: http://www.w3schools.com/
When I started with forums I started to play around with the code using simple tags and thing's like <h1> and <b> etc. and used quackit, as mentioned above, as a first reference and then I used w3schools and now I know HTML/CSS to make basic sites and pages.