When it comes to filling in PDF document properties, there are a few standard fields that you should consider filling in. As you mentioned, the Author and Title fields are obvious and important.
In addition to those, you can also consider filling in the following fields:
Subject: This field can be used to provide a brief description of the content of the PDF. In your case, you could use this field to include the title of each chapter.
Keywords: This field can be used to include relevant keywords that describe the content of the PDF. This can be helpful for search engines and readers who are looking for specific information.
ISBN: If your book has an ISBN, you can include it in the document properties. This can be useful for readers who want to purchase a physical copy of the book.
Copyright: You can include copyright information in the PDF document properties, including the copyright holder and year of publication.
As for style guides for PDF ebooks, there are a few things to keep in mind.
Firstly, you should make sure that your PDF is optimized for reading on a screen. This means choosing a font that is easy to read, using a legible font size, and formatting the text so that it is easy to follow.
In addition to that, you may want to consider adding bookmarks and a table of contents to your PDF. This can help readers navigate the content more easily. You can also consider adding hyperlinks to external resources or other parts of the PDF.
Finally, if you are looking for a tool to help you convert your scanned chapters into a single PDF file, you can try Deftpdf.
Deftpdf offers a PDF converter that allows you to combine multiple PDF files into one document. Additionally, you can use their OCR feature to make the text in your scanned PDF searchable and editable.
Full disclosure: We're the developer of the tool we recommend and we think it can help you, hence the recommendation. We would be happy to see you try it to help you and you can send a message/comment if there's further assistance needed.