You do not need to be good at maths, or a genius at crosswords; you do not need ever to have played the game before. What you do need, though, is ''The Little Book of Sudoku'', a genuinely pocket-sized book that contains more than 200 puzzles of five levels of difficulty and (for those who need a little help), their answers. Sudoku is completely addictive and has been sweeping the nation since the first puzzle appeared in a newspaper late in 2004. The 200+ puzzles in ''The Little Book of Sudoku'' will entice the novice, enthral the casual player, and tax the expert. Above all, the book will not only test a reader's skills, but help to develop them to a very high level, while ensuring many hours of captivating, if sometimes frustrating, fun.