Operating System

Choosing the operating system is an important choice as it determines what happens next in terms of setting up the rest of the server. Here it is time to start thinking about what roles you want to use, whereas most operating systems can accommodate everything mentioned on this site, taking a role to the extreme like a very popular website will need an OS more suited to the task. Here is the breakdown of the more common operating systems:

OS Type	Examples	Cost	Suitability
Windows Desktop Class	XP, Vista, 7, 8, 8.1, 10	Under £199	For most roles with minimal users
Windows Home Server	Home Server, 2011	Under £100	Tailored to home servers, some limitations
Windows Server Class	2003, 2008, 2012	Over £250	Full server software, may be overkill for some situations
Linux Desktop Class	Ubuntu 14.04 Mint OS	Free	Can be configured to run server roles, but may complex to enable these, Lots of choice
Linux Server Class	Redhat Clear OS	Free - £1000	Lots of choice from simplified configuration to corporate grade solutions

Windows

If looking at Microsoft Server, the first question is cost, a standard version of the most recent Windows 2012 R2 comes in at over £2000 so it is worth looking at alternative solutions.

Based on what is needed, a more standard operating system like Windows 7/8/10 will cater to most, as their stability is what's needed most when running a server. However as a learning tool it really has to be Windows Server. My favourite is Windows Server 2003 simply down to the amount of time spent with it, but after July 2015 it has moved to "end of life" and is no longer supported by Microsoft, it will still work, but any vulnerabilities since the cut off will not be fixed and will cause problems. Even so, due to its end of life prices are cheap and can still be useful as a learning tool. The next step up is Windows Server 2008, prices are also low and due to the longevity of 2003 it is often overlooked, but it is still supported until January 2020 which makes it safer online.

Linux

Where the choice of Windows is limited to half a dozen, there are countless possibilities of Linux operating systems, all "distros" start with a basic Linux kernel (like DOS on early Windows) but after that the systems are free to develop and tailor themselves to a host of different working environments. Apart from a few exceptions such as Red Hat Linux, most are free to download and install, so many can be tested for a good fit without making a financial commitment.

For a home server I recommend Clear OS, mainly for its web management interface, for a beginner all the needed settings are easily available by using a website hosted on the server. The free version is available on the website if you look past the paid solutions. SME Server is a similar alternative but the console settings can easily put off a new user.

If a more traditional desktop solution is preferred, I recommend Ubuntu server, while it does not have the stature of Red Hat as the Linux server solution, it is free to use and has by far the biggest community supporting it, so any problem encountered, more likely a solution is a quick search away.