First time building a Computer from scratch

[Thornne]

Hallo fellow gamers!!!!
I've decided to build a tower gaming computer after having used gaming laptops for quite some time. I do a lot of gaming very often and I want to build a computer that's a solid step up from the laptop I'm using without burning my wallet.
The laptop I'm using is the Republic of Gamers Asus laptop. It has 8gbs of RAM, 1 TB of memory, windows 7, 17" screen (1600x900 res) and Nvidia GTX 560m video card.

I'm rather new to building a tower, which basically means, I'm really unsure where to get started so I'm hoping you all can help me get going.

Basically I'm looking for a tower than can handle WoW on ultra settings at 60fps, as well as most newer games on the very high end settings (Far Cry 3, Assassin's Creed 3, etc.)

I want to keep total cost around $800.
Res would be 1920x1080 (23" monitor) with a possible second monitor in the future.
I don't use any other big programs
I'm in the US
SSD recommendation are welcome too, although I will most likely wait and upgrade that later.

I'm gonna use either windows 7 or 8, but I've heard some not so great things about w8 so if anyone could provide feedback on that, it would be greatly appreciated.

I've already got all the peripherals (monitor, keyboard, mouse, headset/speakers)

[chazus]

Marest's Sample Build 700 seems a good fit.

Budget Gaming 700
MoBo: MSI H77MA-G43 – $84.99
CPU: Intel i5 3350P – $189.99
RAM: G.Skill 1600MHz 2x4GB – $34.99
GPU: HIS IceQ Radeon 7870 GHz Edition – $224.99
HDD: WD Caviar Blue 500GB – $64.99
PSU: XFX ProSeries 450W – $52.99 Review
Case: Rosewill Challenger – $49.99

[lalangamena]

don't take PSU less than 650W !

450W PSU wont even turn the fan on the 7870 GPU...

[Noctua]

don't take PSU less than 650W !

450W PSU wont even turn the fan on the 7870 GPU...

Umm.... what?
Why do you say this?

[chazus]

don't take PSU less than 650W !

450W PSU wont even turn the fan on the 7870 GPU...

Eh. A 7870 only uses about ~130 watts. A 450w power supply is perfectly fine.

130w for GPU, ~60w for CPU, 5-10w for RAM, 5-10w, ~10-20w for Mobo. So we're looking at probably about 250-350 watts tops.

Hardware is using less and less power these days, and is getting more and more efficient at using it, rather than burning it.

My GeForce 460 used 160w. I upgraded to a 660, a good 50% performance increase... And it uses ~130w. My computer literally uses less power now.

[Roblivion]

don't take PSU less than 650W !

450W PSU wont even turn the fan on the 7870 GPU...

450 Watts won't turn on a 7870 fan.... Wha wha whaaat?