Book is a part of our life without it a single moment of our life seems dull and if you have good reading habit than it will broaden your view and knowledge and it is not necessary to read those books which is for exam or for promotional exam or any kind of competitive exam . Some books help you to reduce your monotonousness and make you refresh by its unique story and make you feel happy.
If you are a student of competitive exam than you should choose those books which gives you vast discussion on any topic and never based your study on multiple choice question as it would hamper your process of gaining knowledge.
If you are a professional than to keep you update you should read books related to your profession and thus you can make you smart in your space.
If you are a business man than make you updated with such books where every week new journal published in reference to your business that will help you to make you update with your business.
Beside these one can choose the mood of recreation of your own by choosing some good books about tales autobiography etc.