Go to "Create User" under User Management

Mouse over "Management", then "Users" and click on "Create User".

Alternatively, there is a button to create a user on the "Manage Users" page

Fill in the information you need about the user

At the minimum you must specify a Username.  If you do not specify a password the password will default to the user's username.  You can give the user an appropriate Role and appropriate Groups here if you want.

Provide an Email Address so your user will get notified if they need to submit a time, expense, or custom sheet, as well as to allow the user to reset their own password.

Save your changes

At the bottom of the page is a Save button.  Click this when you are done.  If you want to create multiple users click Save and New instead to be brought to a new Create User page.