For almost two decades , Microsoft and oracle have teamed up to integrate their products for customers. Combining the strength of Microsoft and Oracle software means easier management and increased productivity through integration and interoperability.
I have found a great site which provide all information to work on .NET Framework thorough support for Microsoft Visual Studio 2005 and Oracles databases.
It also contains lots of case studies for integrating Microsoft and Oracle application.
here is the link for the site.