Promote ticket sales via Facebook
You would need to create a Facebook Fan Page to make use of Facebook Events' Buy Tickets feature that would link to your event page. Click here to create a fanpage: https://www.facebook.com/help/194555227342272
Set up an event page with EventNook and you can learn how to by clicking here.
Go to your Facebook Business/Fan Page status update, click on Offer, Event + and then click Event.
You would see the following:
At Tickets, enter EventNook's unique URL to your event to purchase tickets and register for the event.
Fill up the rest of the required information and click Create.
To know more about details on how you create a Facebook event, go to https://www.facebook.com/help/429428587125183
The following is an example of a real event: