Michelle Obama’s 12-stop jaunt across the country — and an ocean — is not your average book tour. Of course, the former first lady is not your average author. Oprah Winfrey joined Obama Tuesday night at the United Center, home of the Chicago Bulls and Blackhawks, as she begins the tour touting the already best-selling “Becoming.” Obama will come to Denver’s Pepsi Center in exactly one month’s time– Dec.