Linux is a very popular platform. Not just because it is free but also because it is reliable and supports anything you can imagine. A popular setup is a Linux server without any graphical user interface. It can be used for web hosting, as a file server, as a database server, or for anything you need. Most people comfortable with Windows operating system are afraid to start thinking in a different way. In fact, installing and using Linux is pretty simple.
Once you decide to go for it you have already made the first step. The next step is to get some basic information about installing Linux. There are many Linux distributions. One that is very popular is Ubuntu. Simply Google for "ubuntu server" and learn about what do you need to install Linux. In general, things are pretty simple. You can install Linux on almost any machine. Your old computer that was replaced some time ago is a perfect choice for Linux. You only need some space on the hard drive, a CD or DVD drive, a network card and a lot of patience.
The first step is to make a bootable CD with the latest Ubuntu server image. Download the image file and burn it on a CD. Then you boot your computer with this CD and start installing Linux. It is a good idea to do this installation next to your main computer with internet accesses. This way you will be able to browse for any problem you may encounter. The most important thing you should know is that for every question you may have, there is an answer on some web page waiting for you. You only have to find it.
The installation process is pretty straight-forward. If you do not understand what the installer is asking you then simply select the default option. Of course, you can also ask Google for it and then choose appropriate option. You should understand that the Linux principle is very different from the Windows one. But once you become familiar with Linux shell and basic commands it will be very easy to work with Linux and to install and configure new software.
Having a Linux server is a great upgrade to your home network. This server will be your reliable storage for large peer-to-peer files, web server for website development or a computer to play with. And remember, sooner or later you will encounter a problem. Something will not work or you will not know how to change some setting. All you have to do is to search for the answer on the web. Web pages offer a giant encyclopedia on Linux.