There are several preferences that you can set by choosing Preferences from the Edit menu. I think they're mostly clear, but here you go:

Labels

You can use this panel to set the colors and names of the labels that can be applied to songs in the database.

Fonts

You can use this panel to choose the default fonts for tune lists and tune texts.

Score

This panel allows you to choose a default instrument for playing tunes, and to specify whether the gray control bar in score windows should return to its default position when you open a new window or stay where you put it.

Printing

You can use this panel to define printing margins for your songs. This is particularly useful, for instance, if you want to always add an extra left margin to punch holes for a notebook.