Small network install

I have finally been giving the opportunity to install/administer a small network at my current site. It looks like that all my complaining about being a MCSE with no hands on might change. However, I am very concerned that my lack of hands on might hinder my excitement. I will be working with 12 nodes that I would like to set up in a client server environment. The purpose of the network is to provide a training lab for the company. My initial thought is to expose the employees to 2000 professional and server, while continuing to utilize the NT 4.0 and 95 platform. Any thoughts of a preliminary network design or topology? My emphasis is to make this project simplistic but yet effective. Any help would be appreciated?