I started off knowing very little about the hardware in a PC, but somehow I came to build my own rig. It is supposed to be a budget gaming PC. started off with a budget of £350 but that became £400 and then I just thought f**k the budget just dont spend too much. It took me about 3 hours to build as this was my first PC but it came together well and works fine. I am currently using Ubuntu until I get Windows 10, but it is fine for now. My apu was getting a bit hot so I got a hyper 212 evo and a few more fans, the mobo couldn't support all 6 fans so I got a fan controller for them. It runs most games on the source engine on a high fps such as portal 2 at over 80 fps and csgo at about 60 (not much to brag about but I haven't tried many games yet.) In hindsight, I would have used a better mobo and a smaller case as I am looking to buy a graphics card and my case looks a bit empty as the components are spaced out.
Update: I've recently bought the rx 480 Nitro+ as it was in my price range and it had a good price to performance ratio. BTW I'm not an Amd fanboy, I just happen to have an AMD cpu and gpu.
Update 2: Got tired of low frame rates in Cities Skylines and in certain areas in The Witcher 3 so I decided to get a new processor. I was considering the i5 6500 but I decided on the i5 6600k due to its overclocking capabilities. I chose the MSI Z170A M3 because it was within my budget and it looks nice, and I decided on Kingston Hyperx fury as of how well my old Kingston Beast ram performed.
If you are interested here are some rough benchmarks:
Witcher 3 max settings, Nvidia hairworks: off 60 fps in Velen & Skellige Frame rate drops to about 50-55 in Novigrad and Oxenfurt.
MGS:V max settings around 60 fps and occasionally drops to 55.
Cities Skylines max settings runs at a solid 60fps and runs at about 40fps when zoomed in on densely populated areas.