Question: I want paste button only when I select copy option. When copy option is not selected the paste button should not come on the screen.
How can I do it?

Answer: 
I always found pluralsight tutorials very helpful and they have a couple on MVC3.

<http://www.pluralsight-training.net/microsoft/olt/courses.aspx>

Alternatively check out this article by Jon Galloway which lists lots of tutorials and resources:
<http://weblogs.asp.net/jgalloway/archive/2011/03/17/asp-net-mvc-3-roundup-of-tutorials-videos-labs-and-other-assorted-training-materials.aspx>

Or David Haydens blog: <http://davidhayden.com/blog/dave/archive/2011/01/05/ASPNETMVC3TutorialsIndex.aspx>

Finally of course there is always the asp.net website: <http://www.asp.net/mvc/tutorials>
I wrote a blog post on [Dealing with javascript or JSON results after an AJAX call with Ajax.ActionLink, unobtrusive AJAX and MVC 3](http://www.sharpedgesoftware.com/Blog/2011/02/27/dealing-with-javascript-or-json-results-after-an-ajax-call-with-ajaxactionlink-unobtrusive-ajax-and-) that might help you along.