What permissions do the different user types have?
Please see User Types/Permissions.
How do I delete users from the system?
You can't. Users can be marked inactive so that they no longer have access to the PPM Pro system, however, they cannot be deleted. This allows transactions in the system to be tracked back to the appropriate users.
How do I change a user's "type"?
Navigate to the user's resource record and choose Edit User Info. Select the type from the User Type drop list and save.
How do I delete resources from the system?
Resources can only be deleted if they do not have an associated user, and are not on any entity teams - including task and issue teams. If you feel you should be able to delete a resource but cannot, often there is a sneaky task schedule that prevents a resource from being deleted. To troubleshoot, run a couple of Target=Org, Category=Resource reports. Pick a Task Schedule or Issue Team report source. The results will display all team members, and you'll probably find your resource there.