Giants wrote To be honest if you do not know much about computers I do not reccomend building it. You will most likely plug something in the wrong port, etc. which can fry your computer.

You're probably right, but I want to have a challenging project for this summer, if I screw up, don't feel bad for me lol. I'll probably have my neighbor wire the motherboard, (he does it for a living.) but thank you guys

Your own choice in shell (because I don't know what you like)
Graphics Card: NVidia GT560 w/ 1Gb of memory ($230)
Operating System: windows 7 ($100)
Processor: Intel core i7 or better ($200)
Memory: at least 8GB
Power Supply: 950 watts or higher
Extras: USB 3 Ports, WiFi Enabled
With all these you should be able to play any current game on at least High settings