Every book in Trip Payne''s popular, inexpensive crossword series has become a bestseller. Now, this genius of crossword creation (he had his first puzzles published when he was just in junior high and won the American Crossword Puzzle Tournament a grand three times) is back with a seventh collection. That should make puzzle-loving kids positively ecstatic. The age-appropriate clues include "Aladdin rubbed a magic one," "Famous ____ (brand of cookies)," and "You might use one in a treasure hunt." There''s nothing in here that isn''t worth knowing, nothing that''s obscure or arcane. So, for youngsters it''s lots of fun. Happy solving!