WHS Build (Updated w/ Correct Format)

Hello all! Long time lurker, first time poster (as cliche as that sound).

Approximate Purchase Date: ASAP

Budget Range: $500-600 Before Rebates

System Usage from Most to Least Important: Use as a Windows Media Center Extender with my Xbox 360 and backing up >1TB of data from three home computers.

Parts Not Required: Can be headless as long as I can remote access it.

Preferred Website(s) for Parts: Would like to stay with well known sites such as Newegg, Tigerdirect and/or Amazon.

Country of Origin: United States of America (Ohio)

Parts Preferences: Would prefer small form factor, but not a requirement. Have used intel and AMD, no preference.

Overclocking: Only if the community thinks I would need it?

SLI or Crossfire: Don't believe so

Monitor Resolution: Non required.

Additional Comments: Not really Linux inclined, would prefer Windows Home Server, but I'm open to all options.

Original Message:
I'm looking to get into a WHS server. I'm decent with computers and OS but not enough to get into Linux. I am more concerned about redundancy but I would like to stream my digital media to my Xbox 360 as well.

I have no idea where to begin as far as a parts list. I've looked around online but all the tutorials seem to be over a year old. I would like to stay under $500, but I also want to make sure I get a good system.

Thanks in advance to anyone that can point me in the right direction!!!

-Chad