W3C Tips and Tricks

The W3C's Quality Tips for Webmasters is an excellent source for overall quality of a web site. Here they are for your reference:

• <title>: the most important element of a quality Web page
• Don't use "click here" as link text
• Use standard redirects: don't break the back button!
• Use h1 for top-level heading
• Use the alt attribute to describe the function of each visual
• Don't forget to add a doctype
• Use <link>s in your document
• If You Pick One Color, Pick Them All
• Care With Font Size
• Use international date format
• GIF or PNG?
• Use headings to structure your document
• Choose URIs wisely
• Managing URIs
• Beyond Validation
• Use class with semantics in mind
• Unordered lists: more than just bullets