So, you imported some photos and decided that they must never, ever appear in one of your books. Or, maybe you simply wish to stay organized. In any case, here's how to delete photos from your book project's photo library. *Photos from your iPhoto library can not be deleted. See note below.
Oh, and there's no need to fret; BookSmart makes its own copies of images you load into the program. Deleting an undesired picture from BookSmart will not remove the source JPG or PNG from your computer.
In your book project, make sure "My Photos" is visible and expanded on the left side of your BookSmart screen.
Click on the images that you want to delete. Remember: You can select many pictures at a time by holding down the Shift key and clicking. Hit the Delete key on your keyboard or right-click and select delete.
If you've finished placing all pictures on your pages and you want to reduce your file size to save disk space, you can remove all Unused Images. Simply hit "Sort," choose "Hide Used Images" and then highlight and delete all remaining (and therefore unused images).
*iPhoto images can not be deleted from your BookSmart image library, but you can use the Filter menu to hide all or some of them.