Hai...

I want to eager to learn the N-tier Architucture so please provide any specific artical or sample web project's , i want this in C# coding , then i want to know how toinsert data to database and how to retrive it through n-tier architucture

Text from Wikipedia.

SUMMARY: In software engineering, multi-tier architecture (often referred to as n-tier architecture) is a client-server architecture in which the presentation, the application processing, and the data management are logically separate processes. For example, an application that uses middleware to service data requests between a user and a database employs multi-tier architecture. The most widespread use of "multi-tier architecture" refers to three-tier architecture.

Take a look at an article - Patterns & practices.