Janet. She used to be Michael’s sweet little sister, the spunky costar in Fame and Good Times, the relative innocent in America’s royal (and royally dysfunctional) entertainment family. Used to be. All grown up, Janet Dameta Jackson has parlayed her talent, business acumen, and a sheer force of will into a formidable franchise very much under control. Bart Andrews’ gossipy new biography, Out of the Madness: The Strictly Unauthorized Biography of Janet Jackson, offers several sides of a woman by turns vulnerable and cruel, petulant and generous-and always, always driven. The ambitions of the family that begat the Jackson 5 mirror those of the family’s youngest child, who, two months shy of her 25th birthday, signed a three- album, $32 million deal with Virgin Records. The book explores the birth of Janet’s music career (in Las Vegas, no less!), shows her surviving family squabbles and a disastrous marriage as a teenager, and makes clear the special relationship between Janet and older brother Michael. Andrews spins a good yarn in a book that’s both sturdy biography and good old-fashioned dish. This may not yet be Janet’s planet, but if or when it is, this is one of the books to read to know how she pulled it off.