If you want to start learning about the new Windows 7 Sensor and Location platform, you can now access the Beta MSDN SDK documents online!
Here's a couple of starting points:
Sensor SDK BETA documentation
Location SDK BETA documentation
With this documentation, you can learn how to write sensor-enabled applications with the Win32 COM Sensor API. You can also learn how to add location awareness to your apps with the Win32 COM Location API, or the Location scripting interface.