Past pop culture has skewed pirates as dirty, barbaric men that bury their treasure and many believed were folklore. But Pirates were very much real people, and they had some of the strictest and progressive working ships throughout history. Ironically, pirate ships were typically well-organized and often had a Code of Conduct document which discouraged gambling and sometimes even drinking, so the crew could be on alert at all times.
The book A General History of the Robberies and Murders of the most notorious Pyrates by Captain Charles Johnson gives an unprecedented view of pirates and influences popular conceptions of pirates. This book was the first to introduce the notion of pirates wearing eye patches, having wooden legs and making the pirate a mythical character. One of the most famous pirates is Sir Francis Drake, an English pirate that was first to navigate the globe while stealing treasure from Spanish ports. He was even knighted upon return by Queen Elizabeth I, making any documents and early books on his voyage worth thousands of dollars!
Another famous pirate, Bartholomew Roberts, had a lucrative careers as a pirate. Articles by Roberts are sure to be great "treasure" for any pirate collection.