Database would be the best and the most real world solution for this but if you do want to write and read from a file, you will need to make your classes implement Serializable. From there you can look up several tutorials on writing and reading those objects back from a file.
Another solution would be serialization to XML or JSON using for instance jaxb.
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.