Navigate to Administer › User management › Users and then click on the "Add user" tab which should take you to http://www.math.neu.edu/admin/user/user/create.
Populate the Username, E-mail Address, and Password fields. The convention for usernames seems to be f.lastname where 'f' is the person's first initial. Do not use a stupid password here. Make something up nonsensical that is hard to guess. The user will choose his own password later anyway.
Press Create new account when you are done.
- You will see an informational message near the top of your screen with a yellow background. Click on the username displayed there.
Click on Create the user's Profile.
- Populate the fields in the profile.