I know that Design pattern is reusable accepted solution and proven solution for problem. But in real life scenario when and how to use the design patterns in .NET application. Do you have such kind of Problem Solution kind approach document / white paper or any other resource to describe detailed on .NET PRACTICAL design pattern.
There are lots of design patterns that is already available with .net framework to make things easy in programming, For example DbProviderFactory is the class that lets you create DataConnection with multiple provider:
This book just released in 11/01/2012 covers all 23 patterns using C# as well as a couple of others in the GoF book on the same subject. It includes simple examples on each and when to use them.
Design Patterns 1 of 3 - Creational Design Patterns
http://www.codeproject.com/Articles/430590/Design-Patterns-1-of-3-Creational-Design-Patterns
Design Patterns 2 of 3 - Structural Design Patterns
http://www.codeproject.com/Articles/438922/Design-Patterns-2-of-3-Structural-Design-Patterns
Design Patterns 3 of 3 - Behavioral Design Patterns
http://www.codeproject.com/Articles/455228/Design-Patterns-3-of-3-Behavioral-Design-Patterns