Where there is nothing, there is nothing to organise.
The library is created long after the book. One may build bookcases with the intent to fill them, but the labels will be wrong and the shelves will have too little headroom. Eventually, the perverse urge to find books that fit the shelves will come.
Buy a book first and read it.
A single book is already organised.
After reading the book and finding it valuable enough to keep, simply keep it. Who knows how big or small the next book will be, or what language it will be in, or what it will be about? Any free corner is an adequate place to leave a single finished book.
Buy another book.
When there are two, distinctions finally become apparent.
The finished book may sit underneath the new book; Thus an ordering is established. Finally it is time to organise! But only thoughtlessly and effortlessly.
Buy more books.
When it become difficult to pull the desired book from the stack, only then is it finally time to start thinking about a shelf. How many and how to arrange the books becomes obvious now that they are here. If it were another set of books, perhaps they would be arranged another way.
Arrange your books.
If you can’t put a stack of books down, your problem isn’t organisation; You have too many books.
Get rid of some books.