HTML gives your page the basic framework, but it's ability to give it cool formatting is limited.The next step is to learn CSS. Content is nothing without presentation, and CSS will give you the power to breathe life into a History lecture. It is the closest you can come to doing magic without going to Hogwarts!
This site uses stylesheets extensively, so I hope you are using a CSS compliant browser. This is quite likely, as all modern browsers support CSS. Both External and Embedded stylesheets find a place, but Inline styles have been avoided as they are the most difficult to create/alter/remove, as well as making pages larger and slower.
Have I used CSS wisely? 'Fraid not. This site does not degrade well i.e. it doesn't look good on older browsers. I could justify this use/abuse of stylesheets with an essay on the benefits of seperating content from style, faster downloads etc. but I shan't. The truth is I like playing with stylesheets and am not inclined to accomodate viewers who are too lazy to update their browsers.
Learning stylesheets is very easy. I found a free tutorial at webmonkey.com that introduced me to the basics of CSS and also gave me a peek at what one could do with negative margins (sounds interesting, doesn't it?).
The drawback to using CSS is limited (and varying) browser support. If you manage to convince IE to position accurately, Navigator thumbs it's nose at you and the less said about Opera the better (though to be fair, it is very impressive in a few areas). Testing pages on various browsers and modifiying them to accomodate the eccentricities of each takes more time than planning and composing.
Another problem with external stylesheets is the horrible pages you end up with when you save them as HTML only, as the external stylesheet is not saved. Navigator is the worst browser when it comes to saving pages, as it only saves pages in plain HTML format. IE's Web Page Complete feature comes to the rescue, but it does not save background images placed through stylesheets. Opera has the same feature, but it does not work in v6.0!
If you want to know more about various browsers, you're gonna have to read the next page.