Summary: Greg Mortenson - He's written inspiring best sellers, including "Three Cups of Tea," but are the stories all true? 60 Minutes Correspondent Steve Kroft investigates. Howard Buffett - Legendary investor Warren Buffett has chosen his son Howard to succeed him as head of his multibillion dollar holding company. But as Correspondent Lesley Stahl reports, "Howie" -- a farmer -- is no chip off the old block. Novak Djokovic - He's favored to win Wimbledon again this year. He is also a hero to his Serbian people and has quite a sense of humor. Correspondent Bob Simon profiles the number one ranked tennis star, Novak Djokovic.
