Ooo the excitement . .. this lot i waiting for me at 'work' . . .have never put a system together before and will be doing it tonight . . .is it jst a case of following instructions in the motherboard manual?? any pitfalls i should be looking for . .. thx 
XFX ATI Radeon HD 4850 "XXX Edition" 512MB GDDR3
AMD Phenom II X3 Tri Core 720 Black Edition 2.8GHz (Socket AM3)
Asus M4A78-E AMD 790GX (Socket AM3) PCI-Express DDR3 Motherboard
Microsoft Windows Vista Home Premium SP1 64-Bit - OEM (66I-01939)
Corsair XMS3 4GB DDR3 10666C9 1333MHz TwinX Dual Channel Kit (2x2GB) (TW3X4G1333C9)
OCZ StealthXStream 500w Silent ATX2 Power Supply
Samsung SpinPoint F1 320GB SATA-II 16MB Cache - OEM (HD322HJ)
Coolermaster Elite 335 Case - Black (No PSU)
Sunbeam Core Contact Freezer CPU Cooler (Socket 754/939/940/AM2/AM3/LGA775)
Pioneer DVR-216DBK 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM

XFX ATI Radeon HD 4850 "XXX Edition" 512MB GDDR3
AMD Phenom II X3 Tri Core 720 Black Edition 2.8GHz (Socket AM3)
Asus M4A78-E AMD 790GX (Socket AM3) PCI-Express DDR3 Motherboard
Microsoft Windows Vista Home Premium SP1 64-Bit - OEM (66I-01939)
Corsair XMS3 4GB DDR3 10666C9 1333MHz TwinX Dual Channel Kit (2x2GB) (TW3X4G1333C9)
OCZ StealthXStream 500w Silent ATX2 Power Supply
Samsung SpinPoint F1 320GB SATA-II 16MB Cache - OEM (HD322HJ)
Coolermaster Elite 335 Case - Black (No PSU)
Sunbeam Core Contact Freezer CPU Cooler (Socket 754/939/940/AM2/AM3/LGA775)
Pioneer DVR-216DBK 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM