How often, if ever, do you go back and change your hubs?

Once in a month, sometimes once in two weeks. I am not sure if search engines like you to change article every day. I tried with some hubs, the reaction of search engines was negative.

But maybe this is just my experience. Fresh content is definitely a must if you have a site. Its' part of algorithm.

The more content the better. I do not know how they look at article stuff. Wikipedia updates its' articles almost daily.

If there is somebody who can add something to this or that article. Hope that helped.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.