Picture guest:

Enter "Chris Sawyer" as a guest name to have them walk around and take pictures of your park.

Painting guest:

Enter "Simon Foster" as a guest name to have them walk around and paint pictures in your park.

Waving guest:

Enter "Katie Brayshaw" as a guest name to have them walk around and wave to everyone they meet.

Hungry guest:

Enter "Tony Day" as a guest name.

Happy guest:

Enter "Melanie Warn" as a guest name.

Double payment for rides guest:

Enter "John Mace" as a guest name.

"Wow!" thinking guest:

Enter "John Wardley" as a guest name.

Faster Go-Karts:

Enter "Damon Hill" as a guest name. Enter "Michael Schumacher" as a guest name to race even faster.

Hints:

When playing a new scenario for the first time, spend a few minutes looking at it, making some adjustments and gauging their effects, and so on, without worrying about how well you're doing. Then exit without saving and restart the scenario with a better idea of how to attack it.

Bathrooms: I know they're boring, but they can have a big effect on your park rating.

In the Arid Heights scenario, don't forget that you can put in grass. The scenario starts off looking like a sandbox, but it doesn't have to end that way