Codecademy is a great website to get a tast of HTML and CSS. It has a bunch of free lessons which will get you on the right track to developing a website. Codecademy also has lessons for other programming languages, such JavaScript, Java and PHP to name a few.
Scratch is a really basic introduction to programming. It will teach the ideas behind programming concept in a fun, game-like manner. You can create some pretty complex games with its simple drag and drop method of making a program.