I originally learned the basics of HTML and CSS on some old Pokémon fansite, but I got to where I am today thanks to Home and Learn's free Web Design tutorials. I highly recommend the course to anyone interested in making websites. It's very easy to follow.
Other useful web design links:
- W3C Markup Validator - Very helpful at catching coding mistakes in your page.
- W3C CSS Validator - Same as above, but for CSS.
- Can I Use... - Info on which browsers support fancy HTML5 and CSS3 stuff.
- CSS3 Generator - Does fancy CSS3 stuff for you.
- CSS Float rules - This really helped me understand how floats work.
- Table Border Style Wizard - Generates styles for tables.
- Color Blender - Generates midpoints between two colors.
Once you've learned the basics, check out my other web design pages for some specific tips and tricks I've found or made that you might find helpful for your own site.