The Network Admin link is only visible after you Create A Network. The menu will appear in the upper right of the menu bar, and is only visible to super admins. It has been moved to a separate location with the admin area, and is available from the admin area of any site, as long as you are logged in as the super admin user.
When visiting Network Admin you will see Dashboard screen. This looks similar to a site dashboard, with one additional widget, and the site specific widgets removed. The Right Now widget has quick links to the Create a Site and Create a users screens, as well as search boxes to quickly find sites and users.
Each screen is accessed via the main navigation menu, is presented in the boxes below. The links in those boxes will lead you to sections of this article describing those screens. From those sections, you can navigate to articles detailing more information about each screen. Also, WordPress Screenshots shows examples of all the screens.
The Dashboard is information central and tells you about your network sites and provides news of in the WordPress community at large and provide access plugins and other WordPress news.
Use the Network Admin Sites Screen to review and manage the various sites that are part of your network. These sites will be either subdirectory or subdomain sites as determined by how the network was configured. From this Screen access to Info, Users, Themes, and Settings is accessible for each site.
Use the Add New Sites Screen to add new sites to your network.
The Network Admin Themes Screen allows you to control which themes site administrators can use for each site. It does not activate or deactivate which theme a site is currently using. If the network admin disables a theme that is in use, it can still remain selected on that site. If another theme is chosen, the disabled theme will not appear in the site’s Appearance > Themes screen. Themes can be enabled on a site by site basis by the network admin on the Edit Site screen you go to via the Edit action link on the Sites screen.
To add new themes, refer to the Appearance Themes Screen to understand the process of finding and installing new themes for your network.
Use the Theme Editor to edit the various files that comprise your Themes. The Appearance Editor Screen allows you to designate which theme you want to edit then displays the files in that theme. Each file (Template and CSS) in the theme can be edited in the large text box.
The Plugins Screen allow you to add new features to your WordPress network that don't come standard with the default installation. There are a rich variety of available Plugins for WordPress, and plugin installation and management is a snap.
Using the Plugins Editor Screen, you can modify the source code of all your plugins.
The Network Admin Settings Screen is where a network admin sets and changes settings for the network as a whole. The first site is the main site in the network and network settings are pulled from that original site’s options.
Also, Network Setup information that was used when Creating the Network can be accessed.
The Network Admin Updates Screen allows an automated update of the sites in a network. This should be done only after the network has been updated to a new version of WordPress via the Administration > Dashboard > Updates screen.
And Update Network screen is used to update all the sites in your network to the latest version of WordPress.