I've got a couple of non-fiction books I can recommend. Firstly, probably my favourite travel writer, Eric Newby, and the book Slowly Down The Ganges where he and his wife travel down the Indian holy river.
Secondly, I'd go for a book I read about 15 years ago, and although a bit dry in places, it recounts a fascinating journey and was one of the first books I'd ever read about China - The River at the Centre of the World: A Journey Up the Yangtze, and Back in Chinese Time by Simon Winchester.