AutoMapper

AutoMapperConfig.cs

public class AutoMapperConfig
{
    public static void RegisterMappings()
    {
        Mapper.Initialize(c =>
        {
            c.AddProfile<DomainToViewModelMappingProfile>();
            c.AddProfile<ViewModelToDomainMappingProfile>();
        });
    }
}

DomainToViewModelMappingProfile.cs

public class DomainToViewModelMappingProfile : Profile
{
    public override string ProfileName
    {
        get { return "ViewModelToDomainMappings"; }
    }

    protected override void Configure()
    {
        Mapper.CreateMap<UserViewModel, User>();
    }
}

Global.asax.cs

public class MvcApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
        AutoMapperConfig.RegisterMappings();
    }
}

ViewModelToDomainMappingProfile.cs

public class ViewModelToDomainMappingProfile : Profile
    {
        public override string ProfileName
        {
            get { return "DomainToViewModelMappings"; }
        }

        protected override void Configure()
        {
            Mapper.CreateMap<User, UserViewModel>();
        }
    }