I just got through adding a forum to one of my niche sites. This was the first forum I had attempted and was surprised at how simple this was. I figured you folks would like this tip so here goes.
I am using a self-hosted WordPress blog and I searched for the keyword "forum" from the plugin page and found a cool plugin. This plugin is called "Mingle Forum" and allowed me to create a cool looking forum in just a few minutes. I was able to do this without any coding experience, I simply clicked and typed.
Once you download the plugin and activate it you will see a "mingle forum" section on the left in your admin dashboard. Go here and create your categories and the according forums. After you have done this go and set up the user groups if wanted. This is all there is to it.
After you have created the forum you will need to create a new page on your WP blog for the forum. After creating the forum page you will enter [mingleforum] into the page details and save. You now have a forum!
This will allow you to create your own forum on your blog.
I hope you guys enjoy the tip! Good Luck