The CPU looks great, that's pretty standard fare for a new build these days. Your motherboard choice is also fine, and you picked the z68 chipset, so you've done some homework there as well.
The GPU is up to you, what's your budget left over with the other parts purchased?
RAM - either kit is fine, they're essentially the same on the circuit board level. Pick the one that looks better to you, G.Skill is a fantastic brand.
Power Supply - Depends on what you get for your video card, but a 650 watt Corsair unit should be plenty. Don't skimp on this.
Hard Drives - depends on your data storage needs. a 1TB WD Black is going to be spacious AND fast. It's a great drive.
Monitor - personal preferences on this one, but the one you chose looks fine.
Cooling Fan: Not necessary, comes with the CPU and the case
Sound Card: Not unless you do a lot of editing or recording, integrated audio isn't as craptastic as it used to be.
Keyboard & Mouse: I'm a die hard Logitech Trackball user, don't use mice anymore, but the keyboard I usually go for a Microsoft 4000 series ergo. I love the feel and I can type really well. Personal preference here, you just have to find a set that you like and feels good. Going to a store to try some out is never a bad idea.
Buying OS: Windows 7 is the gold standard, buy the Home Premium 64 bit OEM copy. You can only install it on this particular PC, but being that it's $99, that's a pretty damn good deal.
You look like you've got the bases covered, but unfortunately you're coming up on that $800 limit, so you either need to find a way to cut some corners, (usually the motherboard and monitor) and make some room in your budget for a Corsair power supply, Windows 7 and a good video card. Your build is going to go over $1000 if you aren't careful.
Websites to help put them together is tough - Maximum PC has some great how-tos on their site, and YouTube's videos are my second source, look for Tiger Direct's assembly videos (along with MaxPC's)
You can save some money if you go with this motherboard:
and this CPU if you don't intend on overclocking:
This monitor will save you a little there as well:
The Power Supply, and GPUs I recommend: