I want to build a custom PC but I'm a noob - Help Me!

If I sell my xbox 360, games and some other electrical gizmos I have lying around I can get around £400. So consider this amount going towards my needs.

I guess my requirement is partially price dependant but factored into my needs: (bear in mind I'm a complete noob and know nothing)

1. Corsair 650d case looks to fit the bill, as it has good ventilation and looks like components are easy to install into it, it looks stealthy and is at the right price point. But what are the alternatives, there are so many cases? My current old case is a cooler master one and it is built really well so I want my new case to be built as solid as that.

2. I need a good sound card, I'm a bit of a sound whore when it comes to gaming and people have said get the Asus Xonar. Are they right?

3. I'd like my PC to be quiet. That is why I started struggling at whether I should go air cooled, liquid cooled or for a full water cooling loop. I just get completely overwhelmed at this point that I want to give up.

4. Operating system, I've again been told to try and get hold of someone who can get student deals as that can knock of a considerable amount of Windows 7 64 bit.

5. Motherboard, i'd like it to allow over clocking, good bus speeds and have usb 3.0, but I have no idea what to look for in boards and like in Theydon Bois build I saw that he could only fit two RAM modules after fitting all his components.

6. RAM - What do I look for in RAM? 8gig seems to be the amount people put in and RAM is generally cheap so I'm flexible as long as it fits into the board.

7 CPU and GPU - I have no idea what to look for. I do however want my PC to last a good few years without needing to upgrade and the components must be over clockable. Therefore things must be future proof as PC hardware does come down in price as the refresh cycles are not as long as consoles. If I play it smart I can use this to my advantage and pick up better cards later down the line.

8. I do like to try out 3D. I have no idea what cross fire, physix X or sli means.

9. I'd like to get good fps and resolutions. My favourite console game is Metro 2033, I've played it 4 times and as I mentioned before I can accept playing it at acceptable levels as PC hardware is refreshed constantly so If bargains come up I won't feel so hard hit upgrading.

10. Accessories I am treating as separate purchases. I already have a logitech mx revolution mouse and a xbox pad. Also I already have a black pionner dvd drive and plextor dvd burner.

11. What monitor is good? I get confused by all this hz business

12. PSU, aren't they all the same? Apparently they are not so what do I get?

13. I want a SSD for fast boot and the Hard Drives must be decent and quiet.

If you are still reading this and have got this far well done Now what do I build?

 

sorry £1k is my limit. But I'm hoping to spend less.