To create a Admin, e.g. a committee member, select Organisation > Admin and Roles
If the Contact is already in the Admin list, you can adjust their Admin Rights by selecting Edit Admin Rights and clicking on the appropriate check box item to unlock it - or, give them the permissions for that level.
If the Contact isn't yet a Admin, you can add them and give the appropriate Admin Rights.
Events Admin Rights
If a Contact has Events Admin Rights, when logged in they will be able to see their Dashboard, all Events and their own Tasks.
Contacts with Events Admin Rights will be able to create, edit and view all Events. They will be able to view Events created by other Admin that have not been marked as public.
A Contact with Events Admin Rights will also be able to see the Attendees of Events (although not view the Attendees Contact details), as well as view Transactions and issue Invitations to attend.