The great thing about the Souls series is that frankly you can start at any game, and play in any order.
You will probably wind up with a bias towards a particular order after playing all of them. But it's not like, Mass Effect or something.
If you are lore oriented, I'd play 1 through 3 in order blind, then read the shit out of wiki's, the play them again with guides that help you go on a 'lore tour'. But like, you could also just do whatever in any order and still have a great time.