Even an advice columnist can have some rotten headaches--daughter Margo discloses in this generally sympathetic bio. For one thing, there's the identical twin ""Popo,"" better known to the world at large as Abigail Van Buren or ""Dear Abby""--Landers' nemesis both on and off the printed page. They were raised as ""two halves of the same egg"" by the prosperous Friedmans of Sioux City, and began to dissociate from that dubious double identity only when Landers took the first steps toward her own career by taking over the ""Ann Landers"" column of the Chicago Sun-Times in 1955. ""Popo,"" it is hinted, insinuated herself into the early clerical work on the column, then used her experience to sell her services to a rival syndicate. Over the years they've weathered an on-again, off-again feud; as Howard tells it, Abby is a neurotic sort, jealous of her much more gracious sister. Landers, indeed, is never less than queenly--even when her husband of 36 years, self-made millionaire Jules Lederer, leaves her abruptly and shabbily for a younger woman. (In true advice-column style, such handles as ""mid-life crisis"" and ""reversal in fortunes"" are blamed for his caddish behavior; Howard felt victimized by his disavowal of her as well.) Not that Landers is the quintessential mother: exact problems are mooted, but years of asthma masked Howard's inner ""anger"" against her mother; she herself has been married three times (lastly, to actor Ken Howard); and her own three children seem to awaken Landers' grandmotherly instincts very little. Still, Landers' strengths are niftily portrayed: early involvement in Wisconsin Democratic politics; an ability to attract and appreciate influential friends; a kind of earthbound moral sense adaptable to the times (she agreed to oppose Linda Lovelace on a TV talk show before she had any idea what ""Deep Throat"" meant; but when she found out, she clued the audience in too); and the obsessive, almost joyful instincts of a true workaholic. A book that tells most, maybe, about what it takes to ""make it"" as a national pop oracle.