Entertainingly couched as a topical guide for a kid who's about to stay with a middle-class American family of seven decades ago: a survey of slang, customs, technology, and details of daily life, with plenty of telling practical hints—how to ``use your high-tops to anchor your underwear''; ``Before you come, get your shots'' but ``Come back home for modern medical attention''; ``Watch out for false advertising'' and ``Get out...before October 29, 1929''; or, ``give your seat to an older person.'' Clothing, hair-styles, household routines, food, stores, entertainment, fads, travel, and features like Lindbergh's flight and the status of women and minorities are treated in inviting spreads lightened with cartoon-style art, boxed addenda, ``Twenties Firsts,'' and occasional photos. A delightful way to absorb a real sense of the era—and a treasure trove for other authors depicting it. (Nonfiction. 8-12)