Service broker in Sql Server
To understand what service broker can do for you, start from this article.
https://msdn2.microsoft.com/en-US/library/ms166104.aspx
The architecture of service broker is highly scalable and provides granular security features. Learn more about it by reading this article.
https://msdn2.microsoft.com/en-us/library/ms166125(SQL.90).aspx
For security considerations for Service Broker, refer to this link.
https://msdn2.microsoft.com/en-us/library/ms166059(SQL.90).aspx
This link will be specially helpful as it demonstrates some of the common tasks in developing service broker applications.
https://msdn2.microsoft.com/en-us/library/ms166047(SQL.90).aspx
WEBCASTS
Along with the above links, here is a list of some really helpful webcasts which showcase the real world implementation details of service broker.
Introducing Service Broker in SQL Server 2005
SQL Server 2005 for the IT Professional (Part 6 of 11): New Application Design Patterns for Scalability and Availability and the Operational Implications of Service Broker