relax, I know how you feel. The only reason to be nervous is upon the purchase decisions, and we are here to advise you. I was pretty nervous even after advice, but I ended up with the fastest, most reliable computer in my extended family.
http://pcpartpicker.com/p/v4Ej
Definitely get the i5 3570k. Add an aftermarket cooler, their cooling is where intel does its budget cuts. Motherboard is so-so, good choice when it's on sale, but the z77x-d3h is same/cheaper right now. You could go either way with ram. unless you are doing 24/7 extreme gaming, you don't need the latest and greatest graphics card, but I put in a pretty great one for you.
Definitely take a test run before you get into any overclocking.
If you are ever scared that you might mess up, don't be, I accidentally dropped the cpu wrongly into the socket the first time. I was scared that I bent a pin, but it turned out fine. Don't drop you're cpu, though. you COULD break a pin.
touch the case before you touch any parts and de-static yourself between parts or after breaks(b-room).
Stories work wonders, you'll know it when you teach noobs, too