Manager access to specified resources only

Hi all
I've been trying to set MODX so that when a User (David Connors) logs into the manager, he can only see and edit a resource called 'Sandbox'. All other resources should be hidden from him.
On the web, he can view any resources

I've been through several tutorials of varying complexity and don't feel I am any further in. In fact, At one stage I managed to hide the page I was trying to display :-/

I know I need to create a User, add him to a User Group
I know I need to create a Resource Group and drag my 'Sandbox' resource into that
Know I need to give him a Role and update the UserGroup and his resource Group Access

But stitching it all together is a real mystery. Can anyone guide me in the right direction?

BobRay can help - he has quite a number of tutorials and articles about MODx security. This one may be of use to you.

http://bobsguides.com/user-specific-pages.html