Dr. Salk, whose recent divorce made local headlines when he sued for and won custody of his children, now offers a guide which makes the concerns of children ""paramount"" in any divorce settlement and subsequent arrangement. Like Richard Gardner's The Parent's Book about Divorce (1977), he reviews the normal sequence of events adults and children undergo and concentrates on the aftermath problems which require strong parental support and, if they are intense, professional intervention. He warns against acrimonious scenes at home, chance remarks (""Oh, I could kill him for that"") which can distort a very young child's perspective, and decisions that discount a youngster's feelings and preferences. On custody he is adamant about assigning children to the most appropriate parent--often not the mother--and notes with alarm the increasing number of homes in which neither parent really wants the children. In view of his already-listening audience (he's NBC family correspondent) and the number in need of such information, consider this a most reliable referral, although Gardner is more prescriptive about most issues.