How to use the web standards ?

Step 1: use the correct doctype

"Many developers still don't realize that newer browsers look for a DOCTYPE at the top of each page, and will change the way they behave in response to it. Without the correct DOCTYPE, browsers can take your standards-compliant page and render it all wrong."
Read more:
Web Standards for Hard Times - Put a DOCTYPE Atop Every Page
Fixing your site with the right doctype

Step 2: validate your code
"Validators check the syntax of your HTML and CSS to make sure it is correct, and let you know about any errors or ambiguities. It's up to you to figure out how to fix the errors, but usually the mistakes are fairly obvious."
Read more:
What is validation?
Web Standards for Hard Times - Use Those Validators
Validating Australian Museum Online

Step 3: move presentation tags into CSS
The ultimate aim for a website is to separate presentation (colours, fonts, layout, positioning) from content. This is achieved using CSS (Cascading Style Sheets).
Read more:
What is CSS
Advantages of CSS
Disadvantages of CSS
CSS Panic guide

(http://online.uts.edu.au/webapps/portal/frameset.jsp?tab=courses&url=/bin/common/course.pl?course_id=_1506_1, viewed on 20th March 07)