Help Me Build A New Computer

[I LIKE TURTLES]

This stuff is easy for you gaming geniuses, but I have to focus on graduate school and my new assistantship. All I'm looking for is recommendations from the top down. I need to know everything I should buy...hardware, software, etc. Some guidelines:

1. It must also be a functional home computer. (i.e. I gotta have Microsoft Office, etc)

2. It should be good enough to run CSS, L4D, etc...not high-end games but lately my machine is getting 50+ choke everywhere on CSS and L4D crashes my system, despite barely being over the minimum requirements.

3. (Optional) It should be pretty...I like glowing lights/LEDs.

4. I would like to make it cost under $1000. If you don't think that's possible, just say. :P

Thanks in advance for the help.

If you're just looking to build a 'functional' PC, why not just buy a pre-built one? Newegg has a lot of variety when it comes to pre-built systems... only psychos like myself hand pick each individual part we want inside the computer, but it's NOT necessary at all. Here's a random pc i found searching for "i7". you can just pick and choose... biggest variable tends to be the video card. Plus, if you don't know how to actually build a computer from scratch, it makes it that much easier.
As far as software (office)... I go down the torrent route, saves me money to put towards hardware