Retrospectives are very important to agile software development teams. They facilitate continuous improvement. But like most agile style practices they are not as easy as it would first seem. I've worked in a few teams that use retrospectives with different approaches, skills, and the success. So I'm very interested in this skill.
The analogy I like is if that retrospectives give us process refactoring.
This page holds my scratch pad for notes on agile style retrospectives.
InfoQ:How Long Should Retrospectives Last?