National Council of Educational Research and Training (NCERT) books are considered as core books for preparation for UPSC exams. These NCERT books almost broadly cover all the basic aspects of history, geography etc. NCERT books from class 6-12 on subjects like history, geography, science, economics and polity are considered ideal for getting a broad overview of the General Studies portion of the syllabus.This book is considered as an ideal one for Polity as it can alone fetch you 100% marks in the section for the Prelims stage. The language used in this book is lucid and very easy to understand, even for one who is reading Polity for the first time.Art and Culture plays a very important role as UPSC tends to ask lots of questions from this segment. Hence, it is important for all aspirants to know the important topics under this segment. Singhania’s book contains all relevant topics in one place and is considered to be sufficient for this segment.It is also one of the most important segments in the UPSC prelims round. Every year, 5-6 questions are asked from this section. RS Sharma’s India’s Ancient Past is absolutely sufficient for this section. It covers all important topics very briefly. Tamil Nadu’s SCERT book for History is also relevant for the Mains as well. It gives the basic understanding of the subject.Satish Chandra is often regarded as one of the most influential historians and credited to be India’s leading scholar about the Mughal rule. His book on Medieval History is one of the most highly recommended books by all educators.Rajiv Ahir’s book on Modern History gives you a brief overview of the history of Modern India. It is often regarded as a book with high return on investment as a lot of questions are directly asked from this book in Prelims and Mains. The summaries given in the end of the book are quite helpful and recommended to at least go through once.Both are considered equally good for Economy. Sanjiv Verma’s book is a little more precise and crisp whereas Ramesh Singh’s book is a little detailed. If you have time then one should go for Ramesh Singh, if not then one can choose Sanjiv Verma for this section.The Certificate Physical and Human Geography by GC Leong is one of the most recommended books by IAS tutors to cover the geography part in UPSC exams. The book contains all relevant geographical knowledge one needs to know about climate change, deserts, oceans, climatic patterns, glaciers etc.Majid Husain’s Geography of India is one of the highly popular books for Indian Geography. But one is advised to finish the NCERT books first and then move on to Hussain for a detailed study in the subject.The UPSC exam is incomplete without Atlas. Map-based questions are typically asked in the Prelims as well as in Geography optional paper in the mains. Oxford Student Atlas is considered as student’s favourite as it is very easy to understand and use. Orient BlackSwan has maps for ancient civilisations covering the world.Shankar’s book on Environment and Ecology is more than self-sufficient. It is an ultimate source for the Environment section. The book is a little bit detailed. One can make notes and highlight important points for reference.The reason why Lexicon is recommended for Ethics is because it provides keys to solve the case study questions. Lexicon covers all the topics mentioned in the syllabus. An aspirant is recommended to solve at least two case studies in a week as this will suffice preparation for Ethics.Current affairs can be extracted from multiple sources. The Press Information Bureau (PIB) is an ideal source for current affairs. The releases by PIB are very important from an IAS perspective. Other than PIB, daily news analysis of The Hindu is also highly recommended by the experts.