We'll create fresh WordPress site with User Roles installed. You have 20 minutes to test the plugin after that site we'll be deleted.
As an Administrator, WordPress allows you to use the User Roles section to set the permissions and access of the user . You can access it from your Dashboard by clicking on Users > User Roles:
In the User Roles section, you can create Role and determine which admin pages can be viewed and modified by each Role .
Note that you must know which pages can be accessed or modified with the Access and Modify permissions.
You have five pre-defined User Roles in your default WordPress installation – Administrator and Editor and Author and Contributor and Subscriber. While the Administrator Role has all the permissions . You can not delete Administrator. Click on the Action button for one of the User Roles to see the permission fields.
The Edit User Roles section gives you one field – Permission, the Administrator User Roles has all the permissions. However.
I am ready to answer on your questions about plugin usage. Use google+ for that.