Dec 24, 2012
GPU-Asus HD 7870 DirectCU II V2 - £192
CPU-Intel i5 3570k
PSU-Any random brand 650w
MOBO-Asus p8z77
RAM-Corsair vengeance 8gb

These will be the components of the computer i'm going to buy, i -cannot- go over £500 so please don't try to change the parts to something more expensive. I would just like to know if these parts are compatible (mobo,CPU,GPU) as i am a novice in knowledge about computer hardware. I have my own case, monitor, mouse etc.

Yes, they're compatible, be careful with the psu, never go for a cheap one, get a quality psu from xfx, antec, seasonic, corsair, fsp with 500w-600w( it will do for your system).
Also you might need an aftermarket cooler if you want to oc the cpu.