Here is a simple example to populate a dropdownlist!
DataContext is the entity model file where you drag and drop your stored procedure which in turns generate automatic code for the MyStoredProcedureName SP and you can use it like this.
using(DataContext context = new DataContext())
{
var result = context.MyStoredProcedureName();
MyDropDownList.DataSource = result ;
MyDropDownList.DataBind();
}