How can I do this in OpenOffice's Base?
Openoffice.org reports don't offer a lot of control. You can group, but forcing page breaks must be done in the resulting document. You can do it manually with Insert > Break. You can modify the style applied to the subgroup so that it always starts on a new page, or you can modify the table properties (reports are generated in tables).
If you do this using styles, you can save time with each additional report. Create a template with the styles and then import those styles into each generated report. In the generated report, choose Format > Styles and Formatting, click and hold down on the far right icon and choose Load Styles. In the window that appears, select all the checkboxes, then click From File and select the document containing the styles.
This was first published in November 2006