Page numbers are required in your book, but other headers or footers are optional. Make sure they contribute in a positive way, not serve as a distraction. Use a smaller, unobtrusive font with adequate space separating them from the text.
Including the author’s name on one side and the book’s title on the other are common headers. They tend to look best when justified to the outer margins. Setting them up to behave properly in Microsoft Word can be a challenge, however.