advanced excel ms training - Pivot charts

I would like to know more about how to use pivot table. I work on marketing and track our various marketing activity. At the end of a marketing campaign, I would like my staff members to show the different types of activity e.g. advertising, mailing, emails, etc and then the number of people who booked a place at one of our events as a result of that activity (we can tell this from our tracking activities). I then want to enter the cost of each activity and use a Pivot table to calculate the cost per head for each bit of marketing activity that we do. Can you advise?

Kind regards

Richard