Subdomain WordPress Blogs
Configure Sub Domain Blogs
In order to set up sub domains, use a different table prefix for each site. This is configurable in the wp.config.php file.
If you want your blog to appear in a subdomain of your site create the subdomain.
Blog as Root Domain If your blog is going to be in your root folder just create the database as described below.
Select MySQL Databases
Scroll to the Add DB box and enter a data base name for your blog. This can be something like "whatablog" or what ever you wish and click the "Add db" button to create the file.
Then scroll down to add a user. Add a user name and password that you will remember or write it down since you will use it later. Now click the "Add User" button to add the user.
Then croll to the check boxes section and select "All". In the drop down above the check boxes select the user and database you just created above. Now hit the "Add User to Db" to add the user to the data base.
WORDPRESS CONFIGURATION AND UPLOAD
Go to the folder you extracted Wordpress into.
Make a copy of the wp-config-sample.php file.
Rename the copy you just made wp-config.php.
Open the wp-config.php file with a text editor and edit your data base information into the proper fields.
For DB_NAME enter: cpanel-name_database-name-you-created
For DB_USER enter: cpanel-name_user-you-created
For DB_PASSWORD enter: just-the-password-you-created
Leave DB_HOST unchanged
Save the file and exit your editor.
Then using an FTP program log into your web server and change into the folder where your blog is going to reside. If it's in the root of your web space go into the "public_html" folder. If it's going to be in a subdomain go into the "public_html/subdomain-folder".
Upload all the files and folders to the web server. Once all files have been copied make sure they are all on the server.
Multiple Blogs using a Single Database (SEE http://codex.wordpress.org/Installing_Multiple_Blogs)
As with the multiple databases solution described above, the wp-config.php file will vary for each installation. In this case, however, only a single line will be unique to each blog:
$table_prefix = 'wp_'; // example: 'wp_' or 'b2' or 'mylogin_'
WordPress, by default, assigns the table prefix
wp_ to its MySQL database tables, but this prefix can be anything you choose. By using more than one, you create unique identifiers for each blog in your database. For example, let's say you have three blogs to set up, with the names Main, Projects and Test. You want to substitute the prefix
wp_ for each blog's wp-config.php:
$table_prefix = 'main_';
$table_prefix = 'projects_';
$table_prefix = 'test_';
As noted, you may use a prefix of your own making. Those provided here are for example purposes only.
Upload each wp-config.php file to its specific root/installation directory, and run the installation. See Installing WordPress for more information.
OR see: http://www.shouthead.com/legacy/how-to-setup-multi-blogging-with-wordpress-20.html