Roles and tasks should be set up by a network administrator using the iManager Configuration Wizard.
The wizard will launch the first time you run iManager. You must be logged in as a user with admin-equivalency since the schema is extended at this time. It will step you through the creation of the Role-Based Services objects and will let you assign roles and tasks to the user that is currently logged in.
You can launch the iManager Configuration Wizard anytime by clicking Configure > Plug-in Setup and Install > Configure iManager.