Hi Maria,
There are two ways a user can view & modify a project/work item:
- "Super User" permission on the user profile which give the user access to view and modify any project/milestone/task/issue in the system regardless of role (more on permissions here: http://usermanual.clarizen.com/#user-permissions)
- The user's specific role(s) within a project: http://usermanual.clarizen.com/#roles
In your case, you will want to set the Manager field for the work items to delegate control of the planned dates, work, resource assignment for the specific work item (and its children).