What is the usual percentage range of the profit the author gets from selling of the books?
10-12% net profits. 17.5% if you are in a very good negotiating position (the publisher really wants the book).
>Please do suggest any book, website/blog, or other resources that you found particularly useful for learning how to publish a book.
I am in the UK. Don't know if there is a US version: https://www.amazon.co.uk/Writers-Artists-Yearbook-2022/dp/1472982835/ref=pd_lpo_1?pd_rd_i=1472982835&psc=1