How do I find a topic for a nonfiction book or develop a plot for a fiction book
Go through your email for the past year. Find the 10 stories that you have been telling over and over again to friends, family, colleagues.
1. Look at your email
I did this exercise with a friend of mine who has written several books. He said one of his would be about all the times he tried to start a business and it failed (he's now a very successful venture capitalist).
2. What are your "epic fails"?
Write down ten skills you would like to learn or get better at. Now find people who have mastered those skills and interview them. You will find many stories in their lives that they can tell you.
3. What are some skills you want to learn?
For instance, if I say I love baseball, I can write ten articles about baseball right off the bat. Or if I love chess, or investing, or surfing, or whatever. Write down ten things you love and then research each one to find out what interesting history there is or what curious aspects there are that nobody knows about yet. That's a good topic for an article or book.
4. What is something you love?
Every story from your kids' childhood that they will never forget can make for an interesting book or article on parenting (or whatever it is they were doing).