Questions have been raised about the truth of James Frey’s best-selling memoir, “A Million Little Pieces.” “The book, originally published in 2003 by the Nan A. Talese imprint of Doubleday, soared to the top of the best-seller lists in the fall after it was chosen by Oprah Winfrey for her television book club. Ms. Winfrey’s enthusiastic endorsement helped the book to sell more than two million copies last year, making it the second-highest-selling book of 2005, behind only “Harry Potter and the Half-Blood Prince.”