INSERT into SQL Server table using rows of a DataGridView - LINQ version in C#?

I want to do the same thing as the code below -- but using LINQ in C# ( LINQ to SQL ) to do the iterating and inserting.  Please provide exact C# code.  The broader question is how to do basic CRUD operations in LINQ.  I do have a context called "Model1":

I want just very simple statements ... nothing complex.  Just basic CRUD operations.

I managed to get a SELECT working .. but I am not sure how to do an INSERT or UPDATE.

 using (var db = new Model1())
 {
//do a select
var query = from b in db.Customers
                            orderby b.CustID
                            select b;

                //    //Console.WriteLine("All blogs in the database:");
                foreach (var item in query)
                {
                    Console.WriteLine(item.CustID);
                }
}

 using (var db = new Model1())
 {
// do the insert 
}

 using (var db = new Model1())
 {
// do the update
}

 using (var db = new Model1())
 {
// do the delete 
}

private void btnInsert_Click(object sender, EventArgs e)
{
    foreach (DataGridViewRow row in dataGridView1.Rows)
    {
        string constring = @"Data Source=.\SQL2008R2;Initial Catalog=AjaxSamples;Integrated Security=true";
        using (SqlConnection con = new SqlConnection(constring))
        {
            using (SqlCommand cmd = new SqlCommand("INSERT INTO Customers VALUES(@CustomerId, @Name, @Country)", con))
            {
                cmd.Parameters.AddWithValue("@CustomerId", row.Cells["Id"].Value);
                cmd.Parameters.AddWithValue("@Name", row.Cells["Name"].Value);
                cmd.Parameters.AddWithValue("@Country", row.Cells["Country"].Value);
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }
    }
    MessageBox.Show("Records inserted.");
}