In other words...

How do you add more users to the site? How do you add a user?

NOTE: Only site administrators can invite other people into an FMYI site.

In the top right hand corner you will see an "Admin" tab. Next to it there is an arrow you can click on and then choose "Invite people." You can paste in one or more email addresses separated by commas, choose the access level (e.g. General user), and then customize your welcome message before clicking the "Invite people" button.