There are many novels about India, and of course travel guides. The books I mention are some of the ones I have read and are more to give you a feel for life in India. They are in no particular order. Please tell me if you have more to add to this list.
Shantaram by Gregory David Roberts
Family Matters by Rohinton Mistry
Wanderlust and Lipstick: For Women
Travelling to India by Beth Whitman
The White Tiger by Aravind Adiga
The God of Small Things by Arundhati Roy
The Age of Shiva by Manil Suri
Animal's People by Indra Sinha
The Sari Shop
Eat Pray Love by E Gilbert
The Namesake by Jhumpa Lahiri
Q & A by Vikas Swarup
This should keep you busy!