Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Excellent if you are not a minor in the field anymore

'Hays' is truely a classic; one of the few books that will stay close at hand as long as I work (as an applied social scientist). It did not teach me statistics, but since then the book has helped me many times to understand statistics a bit better. Don't use it as an introduction to the field. Reach for this book every time you want to know more about "why so" after you have learned "how to do".