I am interesting in your payment tools. Have you got any sample to show how does it work? I would like to create a form to sell our products.

Yes, we have guides and samples found on the user guides.

Guides: http://www.jotform.com/help/keyword_search.php?rpp=0&search=order+form

And here's a sample product order form that uses Paypal (standard) payment integration https://form.jotform.com/60360974596971. Once you submit the form, it will redirect to Paypal checkout page.

You can also perform a test with your form if you'll create one on the form builder by submitting an actual submission.

Should you require further assistance, let us know.