Writing a book

I'm writing my first non-fiction book on mysticism and occult topics. It's structured more like a curriculum and will probably end up around 500–800 pages.

Right now I'm writing everything in Microsoft Word and organizing chapters, table of contents, and glossary.

A few questions for authors who have written books before:

• Where do you usually get illustrations or diagrams for a book? Do you hire artists, use stock sites, or create them yourself?

• For editing software, do you prefer Grammarly or ProWritingAid for long-form writing? Are there better options?

• What software do you personally use for writing books?

• After finishing the manuscript and illustrations, what are the recommended next steps before publishing?

• Are there any courses, books, or resources that helped you when writing your first book? Would love to hear what tools or workflow worked best for you.