https://www.scan.co.uk/savedbasket/74200bbb-538b-4a4c-a18b-9c01dc9fa254 This was my first build, on top of that you will need an operating system ie (windows 7 or 10, you say you have a pc already so you would be better using a tool like windows easy transfer vs buying a new copy) a cd/blueray drive depending on your needs, I bought a cheap one as it was purely to install my os and depending on whether its a wired connection or a wireless one (would recommend wired) an ethernet cable or wireless connector. Obviously yours does not need to mirror mine, in fact i have upgraded a bit since then, my current GPU is a 4gb gtx970 and if you can afford it I would recommend a GPU at this level, I have also increased my HDD capacity. Another note is if you do plan on following mine I would not recommend the gaming mouse or keyboard and if you intend to play online a decent headset is nice as well. Currently I run fallout 4 on ultra settings with no problems whatsoever. Hope this helps, if you need any more help just send me a message Note: I understand you have a pc already which means you probably have access to a load of parts currently and it might be that all you need to do is upgrade your current one vs a brand new build, this post should only really act as a means to see which parts make up a pc in general. I would also make you aware that there are sites out there that will build your pc for you taking away any liability you might have in damaging parts during assembly, if you are not confident to do it I would suggest this method.