Create a presentation you can deliver which is related to that product. The presentation should be helpful and useful, and mostly pure content. If the webinar is going to be an hour long, then you should have at least 45-50 minutes of good, solid content in there before you ever even talk about the product. An exception would be if the entire point of the webinar is how to use that product.
Using Webinar software participants can share audio, documents and applications with webinar attendees. This is useful when the webinar host is conducting a lecture or information session. While the presenter is speaking they can share desktop applications and documents. Today, many webinar services offer live streaming options or the ability to record your webinar and publish to YouTube and other service later.