I have made this checklist to ensure that whenever I design some site(static or dynamic)it follows web standards.

Anyone interested to make sure their sites are standard compliant may follow these rules without asking formy permission. If you have got your own rules (dictated by the organisation where you work or by the client for whom you work), follow them.

In case you want some more info on it like how to know if it really conforms to web standards, here is the url http://www.ashwineedash.com/template_archives_cat.asp?cat=16

Following is a concise checklist

Check List for Web Standards Compliant Web Sites

Mark ups should be valid. It means tags and attributes used in web pages should be error free. Check validation via free online software (http://validator.w3.org).

All the mark ups should be semantic which means tags are chosen according to their meanings.

Tables should always be used for representing tabular data. To make data tables as accessible as possible it is important to know about and use the various components that can make up a table.

4: Distinction between Presentation and structure

Presentation should be separated from the structure. While HTML or XHTML should be used for structure, CSS should be used for presentation.

XHTML documents begin with elements that tell browsers how to interpret them and validation services how to test them for conformance. The first of these is the DOCTYPE (short for "document type") declaration. This handy little element informs the validation service which version of XHTML or HTML you're using. For reasons known only to a W3C committee member, the word DOCTYPE is always written in all caps.

DOCTYPE declarations are a key component of compliant web pages; your markup and CSS won't validate unless your XHTML source begins with a proper DOCTYPE. In addition, your choice of DOCTYPE affects the way most modern browsers display your site.

There 3 types of DOCType allowed they are Strict, Transitional and Frameset.

XHTML 1.0 Transitional is the one that's closest to the HTML we all know. That is to say, it's the only one that forgives presentational markup structures and deprecated elements and attributes.

All XHTML documents must declare the type of character encoding that was used in their creation, such as Unicode, ISO-8859-1. This is to for correct interpretation by browsers and markup validation purposes

All XHTML element and attribute names must be typed in lowercase, or your document will not validate.

Note that, depending on your server software, the filename mentioned in the src attribute might be case sensitive, but XHTML doesn't care. Class and ID values, on the other hand, are case sensitive.

In HTML, you needn't quote attribute values, but in XHTML, they must be quoted.

In case there is no value to be assigned to an attribute, it should not be declared at all.

In XHTML, every tag that opens must close.

This rule every tag that opens must close makes more sense than HTML's confusing and inconsistent approach, and it might help avoid trouble nobody needs. 

Double dashes can occur only at the beginning and end of an XHTML comment.     

         13: Encode all ‘< ‘and ‘&’ character

Any less than signs "<" that aren't part of a tag must be encoded as "&lt", and any ampersands "&" that aren't part of an entity must be encoded as "&amp;".

The W3C validation service will show a warning message on the nonencoded markup, while a pure XML parser will generate a fatal error.

Avoid using deprecated HTML elements or meaningless elements  to simulate a logical structure where none exists.

A web standard compliant website will work in all browsers but will not look exactly the same in all browsers. It should be taken into consideration that documents that are published on the web will be accessed by a wide variety of browsing devices on several operating systems, with monitors of differing size and quality (or no monitor at all), by users who may have changed their browser’s default text size and other preferences.