User lockdown

[Daniel]

We have installed Edubuntu in an elementary lab on a trial basis.  We
want to lock the student account down so that they can only get to
Firefox and OpenOffice.  We don't want them to get to the terminal nor
any other services.  We want the on-site tech to be able to administer
the boxes.  The tech would either log in as root or as the tech and
then have root capabilities.  Is there someone who can help out with
this or point me in the direction of a RELIABLE