While the civil service aspirant studies text books and newspapers and magazines and coaching material and online blogs and what not, I also recommend some reading during leisure time (say, after Mains Exam, during the lull period till results are out, or even as casual daily reading for those who have a habit) to develop more real perspectives on public service and the role of civil servants:
(This has to be at Number One!) Bureaucrazy Gets Crazier: IAS Unmasked - Konark - M K Kaw
Bullet for Bullet: My Life as a Police Officer - Chinar Publishers - Julio Ribeiro
Not Just An Accountant - Rupa Publications - Vinod Rai
Journeys Through Babudom and Netaland - Rupa Publications - T S R Subramanian
Hind Swaraj - Rajpal Publishing - M K Gandhi
Why I am an Atheist - Bhagat Singh
The Discovery of India - Penguin - Jawaharlal Nehru
Glimpses of World History - Penguin - Jawaharlal Nehru
The Burden of Democracy - Penguin - Pratap Bhanu Mehta
(to be updated...)