First, check the Web authoring frequently asked questions (FAQ) to see if your question has been answered there.
The two most common problems are:
SCRIPT
ElementIf your problem isn't covered by one of the resources above, you can send it to one of the following forums:
comp.infosystems.www.authoring.html
Each of these forums have plenty of experienced HTML authors who are willing to share their expertise. (If you are commenting on a specific page, be sure to provide a URL when you ask your question!)
Please join and contribute to the www-validator
mailing list.
If you just have a small patch or idea and don't want to join the list, feel free to send it directly to the list.