I want to buy Skyrim but from what I understand, you must register it online through something called Steam (whatever the heck that is). I want to install and play the game on a computer that is NOT CONNECTED to the internet. It is a computer that I use specifically for playing games and working on my photography. I do not have it connected to the internet and I have no plans to ever do so. So how can I play Skyrim on that machine?
Yes, you need Steam. You need to connect to the Steam service once. If you're not willing to connect to the Internet on that computer, you are unable to play Skyrim. Simple as that, really.
For the PC you need Steam. You will need to be connected to the Internet for instalaiton and instlaling patches. Then if you are lucky you should be able to play in "offline" mode if you set it up for that.