How were books published before computers, photocopiers, etc?

You mean, how were books printed, not how were they published, I assume. Publishing is a business endeavor that includes editing, printing, marketing and selling the book. The technology you’re referring to is relevant to the production of the physical book itself. The history of printing goes all the way back to the 15th century, when Gutenberg invented the printing press and movable type.

You can read about the history of various types of printing presses here
http://en.wikipedia.org/wiki/Printing