I've never built a computer before so I'm not entirely sure what I'm doing... Tell me if I'm doing anything wrong + not compat

Solution
I think this build is a better option if you just gaming. And you also can overclock this build.
PCPartPicker part list: http://pcpartpicker.com/p/HJ6qCJ
Price breakdown by merchant: http://pcpartpicker.com/p/HJ6qCJ/by_merchant/

CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($49.99 @ Micro Center)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($25.82 @ Amazon)
Motherboard: Asus H81M-E Micro ATX LGA1150 Motherboard ($49.99 @ SuperBiiz)
Memory: Crucial 8GB (1 x 8GB) DDR3-1600 Memory ($34.99 @ SuperBiiz)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.98 @ OutletPC)
Video Card: XFX Radeon R9 280X 3GB Double Dissipation Video Card ($199.99 @ Micro Center)
Power...
Couple of things. Your case has USB 3.0 front panel ports but the motherboard only has USB 2.0 headers. You can either go without the front panel USB ports or buy adapter cables. It would be better to just find a case with 2.0 front panel port. Your power supply is also mediocre. If you could pick a little better one, like a Tier 1 or 2 from Tom's PSU Tiers Chart, it would be better from a performance and component protection standpoint.

http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html


PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor (£78.77 @ CCL Computers)
Motherboard: Asus M5A78L-M/USB3 Micro ATX AM3+ Motherboard (£46.58 @ Amazon UK)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory (£37.99 @ Novatech)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive (£50.34 @ Aria PC)
Video Card: EVGA GeForce GTX 960 2GB SuperSC ACX 2.0+ Video Card (£160.00 @ Aria PC)
Case: NZXT S340 (Black) ATX Mid Tower Case (£56.99 @ Ebuyer)
Power Supply: EVGA 500W 80+ Certified ATX Power Supply (£29.99 @ Aria PC)
Total: £460.66
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-12-12 12:44 GMT+0000

If you are playing at 1080p or less and the games aren't heavily textured, you would be fine with the 2 GB card.
 
I think this build is a better option if you just gaming. And you also can overclock this build.
PCPartPicker part list: http://pcpartpicker.com/p/HJ6qCJ
Price breakdown by merchant: http://pcpartpicker.com/p/HJ6qCJ/by_merchant/

CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($49.99 @ Micro Center)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($25.82 @ Amazon)
Motherboard: Asus H81M-E Micro ATX LGA1150 Motherboard ($49.99 @ SuperBiiz)
Memory: Crucial 8GB (1 x 8GB) DDR3-1600 Memory ($34.99 @ SuperBiiz)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.98 @ OutletPC)
Video Card: XFX Radeon R9 280X 3GB Double Dissipation Video Card ($199.99 @ Micro Center)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($44.99 @ SuperBiiz)
Total: $455.75
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-12-12 08:24 EST-0500
 
Solution
Thanks guys this really helped, i think im just going to change the case to something different as im pretty sure about the motherboard but i need the front ports. Thankyou