The Data Journalism Handbook edited by Jonathan Gray, Liliana Bounegru and Lucy Chambers.
From the webpage:
The Data Journalism Handbook is a free, open source reference book for anyone interested in the emerging field of data journalism.
It was born at a 48 hour workshop at MozFest 2011 in London. It subsequently spilled over into an international, collaborative effort involving dozens of data journalism’s leading advocates and best practitioners – including from the Australian Broadcasting Corporation, the BBC, the Chicago Tribune, Deutsche Welle, the Guardian, the Financial Times, Helsingin Sanomat, La Nacion, the New York Times, ProPublica, the Washington Post, the Texas Tribune, Verdens Gang, Wales Online, Zeit Online and many others.
A practical tome, it is available in English, Russian, French, German and Georgian.
A very useful and highly entertaining read.
Enjoy and recommend it to others!