I don't know about any good courses. But I have read a book called "The Principles of Beautiful Web Design" and it is a pretty good book that describes the basics.
Thats most interesting to learn web design online. I had learnt about web design on some site.and now i get better grip on web design.I hope these site are helpful for you.If you want so do reply...
You definately need to look at w3schools as a great resource for learning and implementing html and learning how to create image and hyperlinks. You can also try installing and editing some web templates in css. It is the best way to get started. Always save a good copy of your work so if you screw something up you can always revert. You can get 10 free css web templates here. Don't be afraid to screw something up. If you are you'll either never learn or you'll just give up. Be sure to visit w3schools as its one of the most advanced libraries of "how to" online for all of us....