I learnt some basic HTML from www.w3schools.com. I can now make text bold, have paragraphs, show images, have background images, then i upload it onto an ftp. Just thought I would share that random fact, doubt i will be able to use these skills as it takes along time to learn how to make a quality sites.
Practice and practice ! Download some free templates and play with their codes. In this way you will understand "how" and "why"
HTML itself is a big field and before switching to CSS, it's a good idea to first improve your skills and have strong command over HTML because i feel if you are not well aware of HTML tags, CSS is useless for you.
Before you take over the internet you should try to use the skills you have at this stage and develop a "real" web site. Try to make it on a topic you love and you will see that soon you will be tempted to improve it and develop it one step further. I think the best way to learn is by doing, as long as you don`t give up you are set to do great things
I'd learn webpage design before, it's not that tough, just need to keep in all the tag correctly then your web will be done. good luck~