You will need to purchase the balloon and a transporter, and pay for lessons to learn how to fly it. Your initial outlay will be expensive, although once qualified you can charge £100s per ride.
Chartered flights will bring in the most money, but you could also take aerial photographs of houses and towns and sell these to home and business owners.
Advertise in the Yellow Pages, specialist magazines, and at fairs and important events, and hand out advertising flyers to interested onlookers.
You could increase your market by contacting businesses and TV programmes, providing them with the ideal prize for summertime competitions.