Once you've got Multisite enabled, you'll need to manage your network of sites. This will consist of:
Configuring the network settings
Creating and managing sites
Installing and activating themes
Installing and deactivating plugins
Installing updates
Let's look at each of these, starting with network settings.
Before you can allow people to start creating sites on your network, you'll need to configure your network settings. Follow these steps:
In the network admin screens, go to Settings | Network Settings.
Under Registration Settings, select the following options:
Allow new registrations: Tick the option that reads Both sites and user accounts can be registered
Registration notification: Tick this
Add New Users: Tick this
Banned names: WordPress adds some of these by default; add more if you would like to ban specific names, including inappropriate language or spammy links
Leave the other fields as they are. Your settings will now look similar to...