The first book that comes to my mind when I'm asked the question "What book do you recommend I read?" is 'The Kaoboys of R&AW" by B.Raman.
It outlines the very base of the 'espionage' agency of India, the R&AW, how it was formed, how it used to be, important milestone and what it is now, in a very simple format, and provides not only an interesting, but also a very enlightening read. This layman's introduction to the R&AW will turn him/her into someone referred to as a "R&AW expert" in his/her friend circle. All thanks to RN Kao, the father of R&AW, and the author, Raman.
Another interesting read is 'Q&A', the basis of Slumdog Millionaire.