Check out this resource:
The Microsoft Office Developer Center has created 101 code samples for SharePoint 2010. These samples cover a wide range of useful tasks from working with lists and document libraries, to using BCS.
Descriptions and Links for individual samples: http://code.msdn.microsoft.com/site/search?f%5B0%5D.Type=Topic&f%5B0%5D.Value=Sharepoint%202010%20101%20code%20samples&f%5B0%5D.Text=Sharepoint%202010%20101%20code%20samples
Full Download Link: http://code.msdn.microsoft.com/SharePoint-2010-101-Code-da251182