• For this you need two tiggers on that will add new products to the history table (after insert) and another to insert a new record when a product is updated. You can access the "old" data by using the deleted table. When an update occurs the new data is available via the inserted table and the data before update is available in the deleted table.

    This link has a basic article on setting up triggers:

    http://www.4guysfromrolla.com/webtech/091901-1.shtml