Keeping the punters under control.

I have landed a new job. I am fairly compu-savvy but..part of the deal is that I am being given a 12 Workstation network to manage. It is a cyber cafe type of thing. There is no Cafe Software but we are getting some. I want to turn off the ability of customers to install software readjust settings and mess with the network generally. I also want to keep this job. I realise that Windows has this ability that is simply beyond account users. I understand I can lock down certain things. This is what I want to do. I would really appreciate help so I can do my job properly.I have downloaded ork tools, am I on the right track? Help.