ilovearduinosomuch:
Let's say I have my shift register, and I only need to send two bits to the B and C segment to make a number 1. All I would need to do is send serial out and make it something like (if segments are in alphabetical order abcdefg D.P) "01100000" which is the byte of data I would send?
It depends how you wire it up.
Have you seen this?
http://www.thebox.myzen.co.uk/Tutorial/Arrays.html