The syllabus of the 'General studies' paper for the prelims exam is very vast and sketchy. In order to make things simple for you, the Civil Service India has gone through the question papers of past several years to prepare resources for you. This is being done after understanding the focus area of this paper and identifying the static and dynamic part of the questions. The static questions are from the subjects like History, geography, economics, political science etc.while the dynamic part is the Current affairs.
As the static part requires thorough reading and understanding of the concepts of the specific subject, Civil Service India have compiled a list of booksand study material that can be helpful to you for your preparation of the General Studies paper for the prelims exam. These references are basic but must resources and have to be covered if you are preparing for the Prelims exam. We may like to advise you to buy the most recent edition becausemany of these resources are being edited each year.
As far as the Current Affairs is concerned, this forms the dynamic part of the question paper and monthly and weekly magazinesplus daily newspapers are its ideal resources. We have recommended some resources that may be useful to you but you can pick and choose other resources that may cover the dynamic part of the general studies paper in the prelims exam.