Team Site Configuration

Question

Hi,

  We have created one Team Site and added few folders as per department in shared Library. We have created Users in active Directory on Windows 2008 as Domain User. We have given permissions to User to folders as per Department. But user got Access Denied Error. But When I added them as Administrator in "Member of" User's Property. They got access and working as per permission. But they have access to Central Administration too which we want to restrict.

  Shall we restrict user from Central Administration or we need to restrict them by Domain User's Permissions. 

  Any help appreciated.

Regards,

 Vikram