This guidance helps architects and developers design, build, test, deploy and upgrade SharePoint intranet applications. A reference implementation that is named the Contoso Training Management application demonstrates solutions to common architectural, development, and application lifecycle management challenges.

This guidance discusses the following:

• Architectural decisions about patterns, feature factoring, and packaging.
• Design tradeoffs for common decisions many developers encounter, such as when to use SharePoint lists or a database to store information.
• Implementation examples that are demonstrated in the Training Management application and in the QuickStarts.
• How to design for testability, create unit tests, and run continuous integration.
• How to set up different environments including the development, build, test, staging, and production environments.
• How to manage the application life cycle through development, test, deployment, and upgrading.
• Team-based intranet application development.

http://msdn.microsoft.com/en-us/library/dd203468.aspx