Enjoyed the series. Found I had to make this change in the header insert.  Otherwise I get a datetime conversion error. 

 51         INSERT INTO OrderHeader (OrderNumber, OrderDate, CustomerNumber, OrderDate)   

   52         SELECT

   53             x.header.value('@orderNumber[1]', 'varchar(20)') as OrderNumber,

   54             x.header.value('@customerNumber[1]', 'varchar(20)') as customerNumber,

   55             x.header.value('@orderDate[1]', 'datetime') as OrderDate

   56             FROM @OrderInfo.nodes('//salesOrder') as x(header)