These excellent books may give some insight into time travel. Most links are affiliate links to Amazon.com, but I have personally read and enjoyed all these books except the last.
Fiction:
Madeline L'Engle - A Wrinkle in Time
Audrey Niffenegger - The Time Traveler's Wife
Harry Turtledove (ed.) - The Best Time Travel Stories of the 20th Century
Nonfiction:
Paul Davies - How to Build a Time Machine
More books: