I wasn't going to reply until I read this.
Please do not listen to this guy.
Smeg45 - Whatcha been smokin' bro? I don't care if it has "Pentium" in the name. It's a sandy bridge dual core, plenty fast for most games today. Most games aren't even CPU bound anyways. as for only dual core, you've got to be kidding. You do realize that 98% of games cannot take advantage of more than 2 cores right? As for the 6770, no, he will not have to reduce settings on most games. My brother has a 5770, he can run most games on high settings smoothly at 1680x1050. 1920x1080p is easily doable. The HDD is a personal preference. Personally, I think 320Gb is plenty, unless you download tons of movies, music, and games. Please, stop spreading false information.
Sunius picked out very balanced and good parts. They will run most games on med-high settings on resolutions 1920x1080 or lower. meediaplus, what games do you plan on playing with the computer, and at what resolution? Unless you want to play like Crysis 2 and BF3 maxed, the machine will do fine, I guarantee it.
As for putting it together, I thought like you once. But I tried it. That was 3-4 years ago, and I have since assembled multiple desktops for relatives and friends. I'm only 19 too, so I'm not some guys with like 30 years experience been doing this for a living either. All you need to do is read up a little bit, maybe watch some youtube videos. There are tons of video tutorials and guides.
Good luck to you.