Setting up MH lights...

[whaase]

I'm wiring up my MH's and I wanted to check and make sure I'm doing this write.

Here is the socket:

http://aquahome.no-ip.com/socket.jpg

Here is the Box:

http://aquahome.no-ip.com/box.jpg

Here is the wire I picked up:

http://aquahome.no-ip.com/wire.jpg

This is the 250w MH ballast:

http://aquahome.no-ip.com/ballast.jpg

Here is the wiring:

http://aquahome.no-ip.com/wires.jpg

Now to my questions.
1) There is multiple voltage wires. Do I just cap off the ones I'm not using? ie. 277v, 347v

2) Does the black wire go to the center of the socket and the white to the outside of the socket?

3) There is 2 common wires. Does it matter which it which?

Thanks, Walter