Creating Semantically Correct Rich Content

If you want to create truly great and useful website content, then you will need to understand the relationship between the code used to display the website text, and the message that you want to communicate.

Why? 

• Longevity of the HTML code - it will be more versatile.
• Search engines rank keyword weight based on semantic structure
• Your markup will make sense to anyone else, whether today or later

In short, headings should have heading markup <h1><h2> etc, paragraphs should use <p>, lists <ul> or <ol>.

http://semantichtml.org/home/

http://www.eionet.europa.eu/software/design/semantichtml

http://brainstormsandraves.com/archives/2002/05/14/dont_fake_your_markup_accessibility_issues_for_css/

http://brainstormsandraves.com/articles/semantics/structure/

Further points:

CSS & font styling

Rich media - maybe separate article