I've been reading the book Pro ASP NET MVC Framework and I'm getting really confused with a lot of things. I've been trying to do some research but I'm finding that with so many different approaches and concepts being thrown at me, it's just making things worse.  
So I have a few questions:

1. I know MVC is supposed to split the functionality into three main things: Model -> Controller -> View. Is the MVC a different approach than the three-tier architecture? Or am I still supposed to be thinking of creating a Data Access Layer and a Business Logic Layer in my project?
2. What exactly are Repositories? It is what acts as my Data Access Layer? Where/How do Repositories fit into the MVC?
3. The book talks about using LINQ to SQL to interact with the database but yet it states that LINQ to SQL will not be supported in the future and that Microsoft is dropping it for the Entity Framework. Where does the Entity Framework fit into the MVC and how do I interact with it?

Thanks in advance for your help!  

Matt