What portion of HST do I pay?

You pay 3.41% HST. This is comprised of 1.76% Provincial and 1.65% Federal.
If the item was purchased and shipped in Ontario you will receive a rebate of: 67% of the 5%(Federal) and 78% on the 8%(Provincial).
If the items are shipped from Quebec or the US it will depend on what taxes are charged upfront.