How to create & populate a DropDownList in ASP.NET MVC 3?

Question

Hi to all.I'm completely new to ASP.NET MVC. I would like to know how to populate a DropDownList with data that is retrieved from databse in ASP.NET MVC 3 using HTML HELPERS.As I googled a lot about this topic but i didn't find the relevant one. So,any please guide me regarding this scenario and also please let me know how to get DropDownList Selected value and how to implement with AutoPost Back feature.

                                      Thanks in Advance