Tax on international 'Net sales?

From Florida...
I intend to sell downloadable software, ebooks and other 'soft' products over the 'Net, and I want to target foreign markets, eg., the UK, Canada, EU, Australia, New Zealand, etc.
Presently, is there any or additional tax I must charge/pay? If so, please tell me the procedure.
If not, what does the future look like for 'Net sales in foreign markets? Any information will be greatly appreciated. Thanks!

There is no additional tax you must pay or charge for sales into foreign markets; however, you must pay federal income tax on your income from the sales.

I should have mentioned that you must get a retail sales certificate from Florida. The sales out of state will be exempt, but the Florida sales will be subject to sales tax.

Dear Loku,
Thanks so much for this information. I didn't think about in-state sales tax responsibility, but that's certainly an issue.. in addition to (of course) federal tax liability. I appreciate you bringing this up. I have to think about how one would give evidence of in-state sales if they are only going through credit cards on the 'net. Perhaps I can include a
'Check here if you're purchasing within Florida' box
on the sales order page, and give notice that the tax (whatever %) will also be charged, prior to customer approval and completion of the sale. Do you think this will fulfill my responsibility?
Also it might be appropriate to set it up w/the merchant / bank account(s) to automatically isolate the collected tax in a separate account, and tie it to the identified numerical sales invoice. Anyway, if you think of any other system or suggestion on this I'm all ears. And I thank you again for your initial advice.

I think your idea about the “check here box if you are purchasing in Florida” would probably be OK, but I am not sure. Perhaps it would be best to run that through the Florida Sales Tax people. I don’t think you need to segregate the sales tax in a separate account.

Thank you Loku.
I appreciate the input. I will indeed contact the Fl tax people. Re: separate account, I realize it isn't necessary, as I've had businesses (brick 'n morter) before. But when the system's in place, the $ is automatically deducted/transferred, no matter how small. For me (at least) it maintains systems and procedures that keep me legal. ..a 'no brainer' so to speak.
I prefer not to mix tax liabilities with other funds. It's not my money anyway, so best not to be tempted. It's simply a personal policy, nothing more.
Again, thank you for your input!

Good luck on the business