Pick a guest, and name him one of the following:

Chris Sawyer            Takes Pictures of Rides 
Simon Foster            Paints Pictures of Rides 
Katie Brayshaw          The guest start waving 
Melany Warn             Increases the happiness of the guest 
John Mace               The guest will pay double fee's on rides 
John Wardly             The guest will constantly "Wow" whenever 
                        he sees a big ride 

To get a lot of money, you can try the following:

Make a ride that attracts lots of people; like a rollercoaster
Make a very long line
Wait for it to fill up with people
Raise  the  price  to about ten dollars (if you put it up to high
than  they'll  just walk out) they'll be forced to pay the ten and you
rake in the dollars, no one will get in line, but you'll have the long
line of people to pay.
After the line empties out, lower the price and wait for the line
to fill up again.