The HydraFramework is a prescriptive development framework for Flex that facilitates rapid development of encapsulated, scalable components and applications.
Adobe Flex is a great platform to work with for creating rich engaging applications of all sizes for the web and now the desktop with AIR. Now we are at Flex version 3 and the next version Flex 4, which is the SDK, and the editor now called Flash Builder are just around the corner.
There are a number of resources, guides and articles that I use regularly when building Flex or AIR applications. This is a growing resource so bookmark the page and feel free to suggest anything that I may have missed.