SQL Server 2005 - A Developer's Perspective
SQL 2005 introduced a ton of new features that developers can take advantage of.
I have compiled a list of resources on SQL 2005 that Microsoft has published for the developer community.
To begin with, I would suggest that you read this general introduction article, which provides an overview of each new developer feature introduced in SQL 2005.
For each of the features described in the above article, here is a list of webcasts that provide further details about them.
Overview of the new Developer features in SQL Server 2005
Introducing ADO.NET 2.0 for SQL Server 2005
Introducing Web Services in SQL Server 2005
Introducing XML in SQL Server 2005
A Primer to Proper SQL Server Development (Part 3 of 10): Best Practices in Data Types and Initial Table Structures
A Primer to Proper SQL Server Development (Part 5 of 10): New Features in Indexing and Index Maintenance Best Practices
BLOGS
The development folks at Microsoft SQL Server team have their own blogs and they are the best source to learn about the internals of SQL Server.
Slava Oks blog on SQL Server memory architecture
https://blogs.msdn.com/slavao/
SQLCLR Development Team's blog
https://blogs.msdn.com/sqlclr/
SQL Programmability and API Development Team blog
https://blogs.msdn.com/sqlprogrammability/
SQL Server Tips and Tricks blog