Page Manager is a helpful feature that can be used to add, delete or move pages within a project you're working on.
Page Manager can be accessed via the Pages option in the lower left.
Once selected, the Media Tray will now show your pages instead of your photos. You can use the slider bar to show later pages in the book or you can click the option to see more of your pages at a glance.
Here you can click the plus signs "+" to add pages or the "x" to delete pages or spreads. The red "x" will delete spreads, the black "x" at the top right corner of pages will delete that page.
You can also click and drag a page or spread to move its location within your book. You may need to scroll down if you have more pages than can be shown on the screen.
Spreads vs Single Pages
When you are in the Picaboo editor, you will always have two active pages which you can edit at any one time, as if the book was laying open in front of you.
You can set whether those two pages are treated as two single pages or as a unit, a single "spread." The place to set this is located under Layouts.
If your pages are set as a "Spread," you can apply a background or photo so that it spreads across both pages.
If your pages are set as "Pages," backgrounds will apply to the two pages separately.
When viewing your pages under the Manage Pages option, you can add pages "+" or delete pages "x" or move pages around, however, whether you can add, delete or move single pages vs two page spreads will depend on what comes after this spot in the book. If you have spreads later in your book, you will not be able to add, delete or move a single page since this will break up the later spreads.
If you want to add/delete/move a single page that has spreads after it, that page would have to be moved to the end of the book where there are no spreads, or all the pages after the one you want to change would need to be switched to "Pages."
When done with the Page Manager, just click the Close option and you will be back in the edit function.