Think of a celebrity. Any famous person will do.
Find your favorite anagram of that person's name. http://wordsmith.org/anagram/ works great for this. This becomes the title of the book.
Find a picture of your celeb. Overlay your Anagram as the title of the book. The subtitle will be "The Unauthorized Biography of _____."
For bonus points you can try to tie in elements of the anagram into the picture, but that's only for die-hards.