If you're at a computer, you can login and create new users. You will find it under Settings>Users. There is a small icon for adding users. It looks like this:
Type in the new user's first name, last name and email.
Choose whether the user is going to be an admin or a standard user. Admins can edit other users whereas standards cannot.
Lastly, press ADD USER and the new user is created. They will receive an email in their inbox to create a password for their account and sign in.
If you want to see how to a user's permissions - click on the button below.