My question is do I need to initialize the discs after this is all done. This is a brand new machine with a brand new install.
'Initializing disks' often refers to erasing them. If you had to initialize them at any point, you would have had to do it BEFORE you install Windows on them. So don't worry about this.
If I ever decide to take off the raid array can it be done? Can I just shut off raid and use one of the hard drives as another hard drive?
Yes. And since you are using RAID 1 (mirror), you can remove either drive and use it by itself without losing any of your data.
Also, if I decide to keep the raid can I partition it after the fact because I have done a raid without a partition?
RAID is done at the hardware level. Your software (including all disk partitioning/formatting utilities) will see the drives as one, single drive in RAID. You will not have to alter your RAID in anyway to partition it again. From here on out, it will be treated as a single disk.
If I raid 1 and want a partition, will the 2nd partition without the os still be mirrored? Will all of the hard drive be mirrored?
Yes. Your drive will be
completely mirrored, sector by sector, beginning to end.
On another computer it will be doing some video editing, what array is best for that? Don't tell me 0 please, as I will never use that because of how volitale it is.
Yes, it is 0. With redudancy, RAID 5 is a good choice, but requires 3 or more drives that are the same size.
True RAID 5 controllers are also very expensive. RAID 1+0 might be a good choice for you if you have the cash for two more drives of the same size. It takes the best of RAID 0 and treats your two pairs of drives as RAID 0 arrays. It then takes both of those RAID 0 arrays and contains them as a single, RAID 1 array. You get speed and you get an exact mirror. However, you use 4 drives and only get the space of 2.