Manage Central Administration (CA) Administrators

How do I give an administrator his Central Administration (CA) permissions?

Add users to the Central Administration site:

1. On the Central Administration Home page, on the 'Site Actions' menu, click 'Site Settings'.
2. On the Site Settings page, under 'Users and Permissions', click 'People and groups'.
3. On the People and Groups: Farm Administrators page, on the 'New' menu, click 'Add Users'.
4. On the Add Users: Central Administration page, in the 'Add Users' section, in the 'Users/Groups' box, enter user names, group names, or e-mail addresses. Separate each entry with a semicolon.
5. In the 'Give Permission' section, select one of the following:
   
   Add users to a SharePoint group. Select this option to give users permissions by adding them to a group that has pre-defined permissions. If you select this option, click a SharePoint group in the corresponding list.
   
   Give users permission directly. Select this option to give permissions to users directly. If you select this option, select the check boxes next to the permission level that you want to give to users.
   
6. Click 'OK'.

Source: Microsoft Technet