Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The best book for explaining puzzle solving methods

There are many books with Sudoku puzzles, but this is the very best for providing a well written explanation of puzzle solving techniques at each level. I've bought about 10 books now, and all have plenty of great puzzles, but this is by far the best for explaining the strategies. Entertaining as well as helpful.For kids starting with Sudoku, I highly recommend buying online the Sudoku for Kids from www.activityvillage.co.uk.