This tutorial will teach new admins and remind old admins how to add a new user. See below the video for a text walk-through.
Once you have logged in find the Users section on the left side of the screen. Under that you will see Add New User. On the add new user screen select the type of user you want, the storage limit, and the amount of storage they can have.
If you are adding more than one user then click the plus symbol. This functionality only works when all users being added have the same profile definition listed in step 2.