old gaming build

Hi there, I'm building my first gaming PC with very little knowledge, was wondering if anyone could help me. The parts I've chosen are all second hand apart from PSU. MSI B75IA-33 Motherboard and I7 3770 CPU £120 CORSAIR Vengence DDR3 1600mhz 8GB 240 pin £26 Seagate 500GB, 7200rpm, SATA III...