Almost every blogger is familiar with discussion forums and take active part in it. They are a good source to learn and share the knowledge. Some popular discussion forums also send huge traffic to blogs. If you want to take your blog to the next level, then you must join these forums. Participating in these forums will give you firm ground of the blogging basics,and will also give good exposure to your blog.
Bloggeries Forum: It is one of the best discussion forums for bloggers. Here you will find tons of useful information on blogging. Lots of relevant sub-forums and very helpful community. Bloggeries also maintain a blog directory, where you can submit your blog for more targeted traffic.
Digital Point Forum: If you want tons of free traffic for your blog, then you must join and take active part in this forum. Very high traffic forum with large community base. Dozens of sub-forums on almost very topic a blogger is concerned with.
Blogging Tips Forum: Yet another discussion forum for bloggers, which is relatively new as compared to digital point or bloggeries. Growing very rapidly and a must join for every blogger. Recently, a chat box has been added to the forum, so that members can directly submit their views, suggestions and similar stuff.
Blog Mastermind Forum: One of my favorite forum with unique theme and layout. Large community with some of the best bloggers giving their valuable advice. Another striking feature is long session expiration time. So even if you come after 10 minutes and start posting, you will not be asked to login again.
Bloggst Forum: Another discussion forum for bloggers with nice green theme. Good community base and very active forum. While creating a new thread, tagging is compulsory, which makes searching the archived threads very easy. Worth registering and actively participating in it.
The Blog Experiment Forum: A good discussion forum for bloggers. Large community base with active members in 3 figures. Here you will find a Developer's Sandbox sub-forum, dedicated for discussions related to technical aspects of blogging.
Blogger Forum: Excellent forum with unique theme based on XOOPS CMS. Blogger Forums also offer free Wordpress themes for forum members. Large community base and very active discussion board. Dedicated section for newbies and well as theme developers. Blogger forum also give RSS feed of each sub-forum. While registering there is a restriction of 10 characters id.
BloggerBuster Forum: A must join forum for those bloggers who have blogs on Google blogger platform. Amanda of BloggerBuster is an expert in blogger hacks and tweaks, and here you will find lots of valuable information about keeping your blogger blog up-to-date.
Blogger Talk Forum: Very lively and informative forum for bloggers. Navigation is very easy with large community base. Registration is easy and quick with no hassle. Lots of sub-forums on diverse topics, making it easy to pick the right thread for posting a question.
SEO Forums For Bloggers
Search Engine Watch Forum: A must join discussion forum for every blogger. Topics covered are SEO, web analytics, promotion strategies and much more. Very large community base with experts giving their valuable advice to newbies on regular basis. Prompt response to queries by the community members.
SitePoint Forum: Another excellent SEO forum with very active community. Here you can get lots of information about various popular PPC programs apart from regular SEO knowledge base. I would highly recommend joining this forum, as the response is prompt and some very valuable archived data.