Dreamweaver Extreme: Five Steps to More Professional Pages with Dreamweaver MX by Drew McLellan; re: Dreamweaver, Dreamweaver UltraDev. [Macromedia – Designer Developer Center]
Here is the suggestions. XHTML is a little hard but doable if you read the manuals.
Step 2: Export your site without template mark-up
Step 3: Future-proof your site with XHTML
Step 4: Tidy up your code with the Apply Source Formatting command
Step 5: Validate your page to find basic errors