First, to be very clear, you can't charge any taxes unless you are registered with HST to remit them.
Your GST number must be on all your invoices.
No, you do not charge HST on exports.
You do charge HST or GST to all Canadians and it is important that you make that clear in your listings.
If you are registered to collect GST/HST, you are eligible for rebates on GST that you were charged by your suppliers on items that were exported. Talk to your accountant about that.
