Architecture guide: ASP.NET, MVC3, Entity Framework, Code-First with existing database, and a few more..

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace Mvc3Demo.Common
{
    public static class QueryExtention
    {
        public static SelectList ToSelectList<T>(this IQueryable<T> query, string dataValueField, string dataTextField, object selectedValue)
        {
            return new SelectList(query, dataValueField, dataTextField, selectedValue ?? -1);
        }

    }
}