Salesforce visualforce page creation

I have a custom object in salesforce (Called events) which is used to manage a training event. I have a second custom object which is used to manage the bookings. It is a child of an opportunity and the events__c object. So we get multiple bookings on an event and then i want to have 1 button on the event object which will produce certificates for each of the names in the booking object. So, i need to create a visual force page which renders as a pdf and pulls the data from the related object in to each page. I think the way to do it would be to have an extra controller to extend the events__c controller which adds the data to a variable and then i can display the data on each page or it uses some sort of loop to render each page with each bit of data from the booking object as well as data from the event of course.