SharePoint SDK resource center | SharePoint 2010

The SDK includes documentation and code samples for Microsoft SharePoint Foundation 2010 and for Microsoft SharePoint Server 2010, which builds upon the SharePoint Foundation 2010 infrastructure.

In addition to documentation, the SDK includes best practices and setup guidance that can help you get started with your own custom applications that build and extend upon SharePoint 2010.

Using the Microsoft SharePoint 2010 SDK Help