Drum notation

I see in instructions for drum notation how to select from the drum palette using a mouse. But I don't understand how to get a selection of drums into the drum palette.

When I started a new score, I selected conga as the instrument for a staff. So when I go to the drum palette, that is the only choice that shows. Should I have created more staves to add more drum choices? Or is there another way to have a greater selection of drum choices show up in the drum palette?

I am interested in auditioning a variety of drums for a couple of beats in a song. What is the easiest way when you are not using a keyboard?

Thanks,
Don