Preliminary IAS (General Studies) Subject Indian History Good books History books of Classes XI and XII - NCERT Freedom Struggle (NET) - Bipin Chandra Subject World Geography - including Indian Geography Good books Principles of Geography (Class XII-Part I, II) General Geography of India (Class XII) Part I - NCERT Geography of India - Resources and Regional Development Part II (Class XII) - NCERT Physical Geography - Leong Atlas Subject Indian Polity Good book Introduction to Indian Constitution - D.D. Basu Related Subject Indian Economy Good books Evolution of Indian Economy - NCERT Indian Economy - Dutt and Sundharam. Indian Economy - Mishra and Puri Subject General Science Good books NCERT books on Science. Science and Technology supplements in the Newspapers and magazines. Subject Current Events of National and International importance. Good books One major National Daily - Either The Times of India or The Hindu. Newsweeklies like India Today or/and Outlook Current Events - Spectrum Subject General Mental Ability Good books No special preparation is required in this area. But some practice may be done from any exercise books or quantitative aptitude. In fact, an intelligent calculation is the basic requirement for this topic.