Here are some forums that are related to web design and development. Note that many of these forums has many sub-forums that cover a large range of topics in many areas such as HTML, Flash, Photoshop. The topic listed are just my impression of their main topic overall forum.
General Web Design and Development Forums
- Sitepoint.com
- Pixel2Life.com
- TutorialFx.com
- Ozzu.com
- DevShed.com
- pxleyes.com
- WebsitePublisher.net
- CreativePro forum
- WebmasterGround.com
- Webmaster-talk.com
- WebmasterAds.com
- WebDesignerForum.co.uk
- LayersMagazine.com
- PhotoshopCafe forum
- FireworksGuruForum.com
- TalkDev.com
- FreeHostForum.com
- WebDigity.com
- TutorialGarden.com
Freelancer Forums
- TalkFreelance.com
- FreelanceGossip.com
CSS Forums
- CSSCreator.com
- WeLoveCSS.com
- Css-Discuss.org - not really a forum, but a discussion list
Wordpress Forums
- Wordpress Support Forum
- Sempre Fi Web Design Forum
- forums.LesterChan.net - Wordpress
- Content Management System forum on Sitepoint
Flash Forums
- Kirupa.com
- ActionScript.org
- FlashKit.com
PHP Forums
- PHPFreaks.com forums
- Killersites.com forums
Application Specific Support forums
- vBulletin.org
- SimpleMachines.org
- Adobe.com support forums
- PayPal Developer Community
- Zen-Cart.com/forum - ZenCart
- phpBB.com
- OSCommerce.com
- HostMonsterForum.com
- oswd.org
- LibraryCopyright.net
- forums.phplist.com
- Joomla.org
- Drupal.org
- JoomlaHacks.com
- JoomlaShack.com
- forums.mozillazine.org
- Coppermine-Gallery.net
- JoomlaContentEditor.net
