Excellent news! :)
For the author pages it is quite straight-forward. For the bibliographic metadata the easiest would be to connect wikidata items with the "Book:" page generated by the (planned) Book Manager extension. The "Book:" page is supposed to provide the book structure and act as a metadata hub for both books with scans (those with Index: page) and books without scans (there was no solution for those yet)
Project page:
https://meta.wikimedia.org/wiki/Book_managementProblem, the extension is not finished yet and neither Molly nor Raylton have time to keep working on it. Some bugs are still open and the fields in the template would need to be maped to Wikidata properties. All this is not relevant for phase 1 (if it is done only for books), but it will become relevant for phase 2.
Is there anyone that could volunteer as an OPW mentor to help a potential student to finish this project?