In this post I will be guiding you how to have different user interface for different blog groups in in community server.
1. Just create new blogs in different blog groups from control panel.
2. Create new master pages for the blogs containing seperate CSS and structure.
3. Now create a copy of Blogs folder in Themes\[themename] folder.
For example I had a folder at the following directory structure.
This folder contains pages to show blogs and blog posts. I copied it and pasted in the same folder (using visual studio 2008, I think this copy-paste would not be possible in VS 2005). Then I renamed it as "MyBlogs".
4. Now set you custom master page to all the pages in the new blog folder (like I have MyBlogs).
5. The trick part is still not done yet. :)
Now open your SiteURL.config file and find location name="weblogs" section. Create a copy of all this section with all its URLs. I have almost 40 to 50 URLs in this section. Don't forget to rename all these URLs otherwise your site can give unexpected links. I renamed all these urls only by appending "2" with their names like the one below.
By modifying you location tag you can easily configure a URL rewriting for this folder. After this modification you are now ready to access your blogs.
To filter you postlist to show posts only from a specific blog you can filter them in Themes\[themename]\[youblogfolder]\postlist.aspx. Just open that page and give a group ID to weblogpostlist control.
For any other help required you can frankly ask here or on my email address firstname.lastname@example.org