8 months for online applications, 13 months for paper) unless the applicant qualifies for expedited Special Handling (usually because they're in a dispute). That costs an extra $550 and we don't think it's worthwhile for you for the following reasons.
Copyright is automatic. That's right, you acquired copyright once you completed your book. Registration is a good idea but not mandatory. Most people register because it provides additional rights in the event of a dispute and because it places the book's title (and contact information) in the registry at the Library of Congress. Registration is mandatory if you wish to file a lawsuit.
Registration is based on filing date, not issue date. The effective date of registration is the date that the Copyright Office receives all of the application materials (not the date it issues the Certificate of Registration).
Copyright won't protect your scaffolding process. You seem concerned with the disclosure of your scaffolding process. Keep in mind that copyright law will not give you the right to control the use or disclosure of your ideas, systems, or methods of operation. (You may be confusing it with patent law which grants exclusive rights for novel, nonobvious processes.) In other words, copyright will allow you to chase someone who copies your book, but not someone who copies your idea. If you're serious about keeping it a secret or controlling the sale or use of your ideas, you should hold off on publishing your book until after you speak with a patent attorney.