My tutorials for Cairngorm that I authored back in 2007 have been by far the most popular thing I have ever blogged. They have been viewed over 150,000 times, and they still get thousands of hits per month. With the move to the new blog, I wanted to be sure that everyone knew how to get to the tutorials (on the archive site).
As a note, I do want to mention that I think that Flex frameworks have moved far beyond Cairngorm and solutions like Swiz and RobotLegs are where your effort should be placed. However, if you are placed on a legacy project where you need to know Cairngorm I truly hope that these tutorials benefit you.