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.
This article has a detailed explanation.
introduction to cqrs
Here you can find sample code for asp.net mvc with cqrs. CQRS with MVC.
Find more video here CQRS with ASP.NET MVC - A Year On
I want to point out the classic example from Greg Young himself: Simple CQRS example
Take a look at Its.CQRS: https://github.com/jonsequitur/Its.Cqrs which is being used in production at Microsoft.