Has anybody purchased any of the reports from Nielsen Norman group? Have they provided useful information? I'm particularly interested in the reports about intranets such as this one: http://www.nngroup.com/reports/intranet-design-annual/
I read through the 2011 version for a project a couple years ago and found it very helpful. Of course your mileage may vary depending on how similar in complexity your own project compares to the examples used. Generally it helped us generate a lot of new ideas around features and organization. It was definitely comprehensive with many good and bad examples that helped steer some of our decisions. However, even in the 2011 version the examples used seemed outdated. I'm sure the research was current, just that Intranets may lag behind in general.
Sometimes they're available for free - see this one to get an idea of what to expect...