I came across a new term named CQRS (Command Query Responsibility Segregation) which states that the conceptual model should be split into command model and query model as a typical CRUD model in which the command and query happens in the same model. The article has all theory information.
I don't understand how I should implement this in a project with ASP.net MVC3, EF 4.3 and jQuery.
Can anybody suggest me how to practically implement it in my project?
CQRS Journey is a good place to start. I also suggest you watch A Journey into CQRS on Channel9.
Anyway, the best thing to learn CQRS is to try it by yourself. For me, I have to learn how to adapt it to my projects for around 6 months.