Instruct: Classify Amazon reviews into positive or negative sentiment
Query: informative book

This book is a wealth of information on stamp dealing. I would recommend it to anyone looking to get into the business. It gives step by step info, pros and cons to the various places and ways to sell stamps including marketing and promotions. The only thing that it lacks is online stamp dealing advice. That was one of the areas that I was interested in. Perhaps this is an idea for another dealer/author.