Use the Delete Current Section tool to delete a section from your book. A section can either be a Poetry Section or a Front or Back section such as an Introduction, About the Author page, etc.
WARNING: You should not delete the first section of poetry (or the only section of poetry if you are not using sections) as it contains page number settings that effects your entire book.
To use this tool first place your cursor in the section you wish to delete.
Then click on the Delete Current Section tool. The following warning will appear:

If you wish to proceed with deleting the section click on Yes. To cancel click on No.
WARNING: If you select Yes the action cannot be undone and the section cannot be retrieved.
The entire section will be removed from your book and also removed from the table of contents if you have one.