For most of us creating a website is entering the great unknown... I have recently been shown a very useful (and free) tool to get an idea of the code and structure behind websites. It only works in Firefox web browser (instead of internet explorer which we probably all use), so you would have to download that first (http://www.mozilla-europe.org/en/firefox/).
The tool is called firebug - just download it: http://getfirebug.com/ , install it and it will automatically work in firefox.
Just open any website. There's a little bug in the lower right hand corner of the browser. If you click on it, it shows you the code, the stylesheet and the layout of the website you are currently looking at. If you click on the html code part you are interested in, the part of website created by this gets even highlighted...