If you are a developer and you are planning to write applications for Windows 7, then one of the best places to start is the Windows 7 Training Kit For Developers which was released today.
The Window 7 Training Kit has everything you need to get started with programming Windows 7, including sample code, videos, presentations, Hands-On Labs (HOLs), etc. Most of the samples come with Visual Studio 2008 projects which means that you can open and debug these samples in Visual Studio 2008!
The training kit has a few prerequisites. Once you download the training kit, click the Prerequisites link to navigate to the page where you can download all the prerequisites.