Setting up the network is really easy. You will find the network options in the tools menu. Once you enable the feature you will be given code to place in your wp-config.php and .htaccess files.
Once these files have been updated you will see the super admin menu in your admin area (it’s the wp-config.php file which generates this menu though the .htaccess file needs to be updated in order for multisite to function properly). From here you can easily add sites and users to your network.
You can allow network sites to use some or all of your installed themes by simply enabling or disabling them on the themes page.
The best thing about multisite is how much control you have over everything. For example, you can allow registers users to add sites to your network or you can add users manually.
Though my favourite feature has to be the ability to set how new websites are setup. You can create a welcome email to new site owners and a welcome owner to users who sign up to network sites. You can also automatically set the first page, post and comment.
There are some additional options like enabling plugins for network site owners and a useful update feature which updates all sites within the network. Media and upload settings can also be set.
Like the sound of WordPress 3.0 Multisite? Then why don’t you install the latest release candidate of WordPress 3.0 and test this great new feature out.