How to make my MVC3 project a Mult Tier (DAL, BLL and UI) pr

Hi,

I am creating an application using MVC3. I follow the examples in -

http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/implementing-the-repository-and-unit-of-work-patterns-in-an-asp-net-mvc-application

Now, I like to make this project a Multi-Tier Application (Data Access Layer, Business Logic Layer and Application Layer).

In the above example I can see the author has a folder called DAL. So, I hope that the content I have to move to the DAL project. What all things should I move to my Business Logic Layer? I am thinking of creating the DLL of Data Access Layer and use it in the Business Logic Layer and the DLL of Business Logic Layer and use it in the Application Layer.

Could you please tell me what all things in the above example will go to each layer? 

Is there any better approach?

Thanks