Use permissions to create different access levels for the people you will allow to log into the admin (BackOffice) and make changes.
The administrator group will be insalled by default and in order to create to create a different permissions group you will first need to set up a new profile (Permissions are allocated to Profiles and profile are allocated to employees which determines what that user can do.)
Go to BackOffice>>Tools>>Permissions.
(Note: Prior to 1.1, this information is likley to be in Tools for the default install)

From the drop down list choose the profile
Now you can simply tick which options you want to apply to this profile. For each option (e.g manufacturers) you can select if users (employees) who are assigned to this profile will be able to View, Add,Edit or Delete.
Tip: There is no save, as you tick the option, the profile is updated automatically