You'll need general studies at every stage of exam - prelims, mains and interview. It is needed throughout your career and life. It contains basics through which you can analyze every day happenings.
In addition to NCERT books, here are some books useful for GS preparation.
1. Polity
Laxmikant's Indian Polity - Tata Mc Graw
2. Geography
NCERT + good notes for understanding planetary winds.
3. History
Ancient and Medival - Old NCERT books
Modern India - Bipin Chandra or Sumit Sarkar
4. Sociology
5. General Science
How? What? Why? from CSIR
The Hindu speaks on scientific facts.
6. Economy
Dutt and Sundaram (bit tough)
Tata McGraw Hill book for Economy
Economic survey -2011
7. National Issues, Bilateral relations, International affairs
The Hindu, Yojana, Kurukshtra, Frontline, Civil Service Times and other magazine you like.
8 For GK, we can refer to Manorama year book.
9 You can follow news in DD or AIR.
9 You can follow news in DD or AIR.
India Year Book is also useful document for most of topics.
