Brown's Guide/Grow/

""Take it easy'' is the worst possible advice for the aging, according to film producer Brown, in this 144-page, tongue-in-cheek collection of shrewd observations on growing old. He cites such vigorous veterans as George Burns, dancer Martha Graham, tycoons Armand Hammer and Tom Carvel who attribute their longevity to continued activity. If the thrice-married author addresses himself primarily to men, his views on relationships between the sexes should nevertheless prove instructive to women, though possibly irritating to feminists. He offers suggestions on managing money, maintaining good health, coping with lapses of memory and bouts of depression, along with tips on etiquette and travel for the elderly. Commenting on what he sees as the rigidity of older people, he counsels, ``Save it for rigor mortis.'' Major ad/promo. (September)