It is an "older" article in a fast growing field, but I recommend to read it if you like to find your way into data journalism.
Guardian :: Has data journalism become curation? - Sometimes. There's now so much data out there in the world that we try to provide the key facts for each story - and finding the right information can be as much of a lengthy journalistic task as finding the right interviewee for an article. We've started providing searches into world government data and international development data.
Our 10 point guide to data journalism - Continue to read Simon Rogers, www.guardian.co.uk