Building network for school learning

Hi,
I have 3 semesters left in a Networking Technology curriculum and want to build a network at home(router/switch/server) to experiment/configure/break/reconfigure...you get the idea. I'm NOT trying to build a 'home' network. I want to simulate a real-world business environment utilizing the same equipment/same software(mostly). I want to act as a System Administrator and deal with all the normal issues DNS, DHCP, security, router/switch configuration, vlans, server configuration, etc., etc... A caveat is that where I live, the only broadband I can get is an air card utilizing the 3g network. Cable or DSL is not available so I don't have/need a modem to connect. That may or may not affect any advice I get.

Anyway, I'm asking for advice on what type of equipment(mainly the model #'s) I need to acquire to achieve this. I would like to stick with Cisco for the router(s)/switch(es)/hubs(?) as that is the school lab equipment. I want to keep this as inexpensive as possible for obvious reasons(starving student here). I know that I can acquire needed software through the school very inexpensively(sometimes free). Any help/suggestions would be greatly appreciated.

Thanks,
Mitch