Though my lecture tomorrow will discuss pirates in several different contexts, the most influential book on this version of the Outlaw archetype is Treasure Island, by Robert Louis Stevenson. The book is available online free, in many different forms:
There are also illustrated scans of original print editions online — check the links at the end of the Wikipedia article linked at the first link in this post. It’s a favorite of young readers, meaning the English in the book, though it is somewhat old-fashioned, should be understandable to most EFL readers, like you! Enjoy!