Good reading list here on online journalism for newbie and vet journalists alike at UK journalism prof Paul Bradshaw's Online Journalism Blog.
And here also on the same site is a great list of free ebooks on journalism, including on investigative reporting.
Among them is journalism prof Mark Lee Hunter's very interesting-looking 209-page The Global Casebook: An anthology for teachers and students of investigative journalism.
A companion to the UNESCO primer on investigative journalism that I blogged about in July, also written by Hunter, The Global Casebook features a fascinating list of dozens of investigative stories from around the world accompanied by notes about how each story was done and its impacts.