As I am learning and working on Asp.Net MVC application, I want to know that what is the better place to write Business Logic and Data Access logic
Business Logic
Data Access logic
Business logic should be in the Model.
Data Access can either be its own later your Controllers call, or automated in an ORM that your Controller will call through repositories.
A walk-through covering this can be found in Nerd Dinner, look for the free download section.