Principles of Practical Natal Astrology comes bundled with exclusive Bonus Gifts, which you will be able to access and download from this website. The instructions on how to register for the Bonus Gifts are in Appendix B of the book.
Simply go to the URL listed in Appendix B, and either register or log in to your account. Your membership will be upgraded automatically to grant you access to the Bonus Gifts. When you're logged in, you'll notice a new "Bonus Gifts" menu item in the top menu bar.
Be sure to sign up for notifications of new Bonus Gifts!