I have developed a joomla based website which is supposed to be used inside a college campus by not more than 1000 members in all. Till now I was working on it locally using xampp. Now I need to test and host it on the campus level on the LAN.
All I have in hand is the joomla site and the computer with a windows OS.

Now could someone please tell me what all software I need to host this website and how to go about it. I am looking for cost free solution. Since there would be just one server and just one website on it so limited license free softwares are welcome.

I have absolutely no knowledge in this field. Not even to get me started. At least give me a point by point direction so that I can start researching on it.

OS: CentOS
Control Panel: Webmin/Usermin
LAMP (Linux, Apache, MySQL, PHP)

All of these are free and resources are abundant on the web.
Google will be your good friend on this aspect.

On windows, you have few options for a control panel. However, if you're hosting just the 1 site, you don't need a CP. It sounds like you just need to be able to remote desktop onto the server.

If not, this link (http://www.webhostingtalk.com/showthread.php?t=532401) has a list of all control panels we know of.

Well yes I just need to host one site.. but how to do that. It must be using some backend softwares.

If you are using windows then you might want to try foxserv http://sourceforge.net/projects/foxserv/
It will install apache, mysql, php
It is also free, so you can try it and if it doesnt do what you want then try soething else :)

You certainly will not need a control panel of any kind no matter whether you opt for a Windows machine or a *nix machine. I assume you wont be needing a mail server so all you need is http and mysql. Once you have the hardware hooked into the lan I am sure if you posted here for some help, someone would be willing to get you setup for free.

My personal free favorite: FreeBSD stable administered through putty and winscp.