MooTools Help! I Don't Know JavaScript! This page contains a great listing of various reference sites, tutorials, etc for HTML, CSS, JavaScript, etc. If you are just getting started in coding, or wanting to bone up on the basics, you can't go wrong by starting here.
The Cascading Style Cheatsheet lists the most useful CSS properties with examples. Comes in very handy.
Dead Centre This is a very simple example of how to horizontally AND vertically center a block using CSS.
Activating the Right Layout Mode Using the Doctype Declaration
In order to deal with both old tag soup written to old browser quirks and new standards-compliant pages, Mozilla (and Mozilla-based browsers), Mac IE 5, Windows IE 6, Safari, Opera 7 and Konqueror 3.2 have two main layout modes. In one mode the layout engine attempts to render conforming pages according the CSS and HTML recommendations. In the other mode the layout engine tries to mimic old browsers. In Mozilla these modes are known as “the Standards mode” and “the Quirks mode” respectively. In this document the same names are used also when referring to the modes of the other browsers.
I am struggling with getting some HTML/css code to work properly in IE. I found some links that might help:
Tom's site: http://tom.me.uk/ has a bunch of great examples of how to do things in IE, like: "I did this in HTML, how do I do it in CSS?" and "CSS Stuff: Emulating position:fixed in IE without scripting"
Explorer Exposed These CSS bugs are all found only in Internet Explorer, versions 5 and higher. To see the demos properly, they must be viewed in IE, of course.
css-discuss mailing list archive a great source of information, with a searchable index
Automatic Labs: Web Application Development And Design
This page uses a very clean CSS layout. A header w/ 2 columns beneath it, all centered on the page. Also the navigation is pure CSS without any mouseovers.