Keep in mind that while azeem40's build is really solid it is also a very high end gaming system. That beast would easily max any game in 1080p.,
If you're budget minded like me or maybe need to free up funds for a monitor& accessories you can deal with dropping the GPU down a few notches.
Today there is a pretty sweet deal on a HD 6950 :
http://slickdeals.net/f/5036334-XFX-Double-D-Radeon-6950-2GB-GDDR5-PCI-Express-2-1-Video-Card-HD-695X-CDFC-Battlefield-3-and-Deus-Ex-Game-Coupons-178-after-30-Rebate-Free-Shipping
It's a fair bit slower than the 7870 but also a lot cheaper and comes with two games. Speed is not a huge difference at 1080p because both cards are high end cards and will just about max any game.. really i'd only consider the 7870 (+$140, about double the price) if you REALLY like computer games or are using a larger resolution.
congrats on building a computer! It's really easy, I mean if you can turn some screws to screw down a motherboard and plug the other parts in the correct slots then you're able to build a PC.
EDIT::
If you need to reduce the price a bit more the CPU he listed has a few slightly cheaper alternatives. Really it's just about the best gaming CPU you can get but you definitely pay a price premium for it.. so there's room to scale down and still have a quality high end gaming PC.
BUT if you can get to a micro-center that is indeed a great non-sale retail price for that chip.