1. From the Server 2012 Start screen, press Windows Key + X. This will open a context menu.
2. Select Computer Management from the context menu. This will open the Computer Management window.
3. Select Local Users and Groups from the navigation tree to the left of the Computer Management window. At this stage you can double click Users in the context window, or click the arrow icon next to Local Users and Groups to reveal the Users and Groups sub categories.
4. To add additional users, right-click on Users and select "New User...". This option is also available from the "Action" menu at the top of the window. At this stage you can add as many user accounts as your deployment requires, and manage accounts that have already been created.
Be sure to later add these new users to the Remote Desktop Users Group: