Extracting all subdirectories from a number of directories

When I export books from Caliber I have a directory with subdirectories by Author name. Under these are subdirectories of the book name. I would like to be able to extract the Book name subdirectories in one go. Then I would like to be able to delete the .opl and .jpg files from resulting directories.
Any ideas?

By extract, do you mean you want to remove the author level, and move everything up one level?

Could you give a few before & after examples using example paths/authors/titles so we have a better idea of what you're aiming for?

I have been playing with find ( after being given advice on another forum) . I find that it I go to the root directory and do a find * I am presented with all the subdirectories. I can then copy all of them to another directory. I then ran find *. ope and got all the old files and deleted them. The same with the .jpg. I now have a directory with subdirectories by book name which only contain epubs. All is now working the way I wanted.
Thanks for your reply though.