You may wish to add multiple users to a database if it is a collaborative project or if you are running a visual analysis using multiple observers. Luscinia allows you to direct MySQL to grant different levels of privilege to different users. "Super-users" in this case would be principle collaborators on the project. "Normal users" would be observers scoring a visual analysis. "Read only" would be users who you simply wish to be able to observer the database, not add anything to it.
First, log-in with your administrative password at the bottom of the Administration page. Next, get your new user to enter values in the "User name" and "Password" fields. Finally, choose the level of access you wish to grant the user, and select the database that they are to be added to.