Back in November, or shortly before, I mentioned NaNoWriMo. They have a blog through Tumblr where they offer writing tips and advice. One post is a list of 46 questions to ask yourself about the various characters in your story.
Is all of it vital information? No.
Will all of these fun facts end up in your story? No.
Will it help you get a better understanding of your characters? Yes.
Will it help you understand that the characters existed before the events of the story and those previous experiences can effect and add colorful detail to the story’s plot? I certainly hope so.
Not sure what I mean by that last one? Check out Orson Scott Card’s Characters and Viewpoint. He discusses this idea in some detail.
May the Muse be with you,