Here are some staples that anybody researching Jesuits or Jesuit Treasure in the New World need to have:
1. "Rules and Precepts of the Jesuit Missions of Northwestern New Spain" by Father Charles Polzer SJ
2. "Missionary in Sonora; the travel reports of Joseph Och, S.J., 1755-1767" by Father Joseph Och SJ (original in German "Glaubenspredigers der S.J. in Neumexico. Nachrichten von seinem Reisen nach dem Spanischen Amerika, seinem dortigen Auftenthalte vom Jahr 1754 bis 1767, und Rückkehr nach Europa 1768. Aus dessen eigenhändigen Aufsätzen" The original journal was supposed to have been destroyed in an Allied Air Raid in 1944 or 1945. The current version was translated by Theodore Treutlein.
3. "Rudo Ensayo" by Father Juan (or Johann) Nentvig SJ
4. "Searching for Arizona's Buried Treasures: A Two Year Odyssey" by Ron Quinn. I include this book, because it was written by the man that found the 82 pounds of gold bars in the 1986 article in Treasure! Magazine. I promised not to publicly use his name, when he granted me permission to use his information (including a lot of pics he had never shared before). Here is the link to this story from my website:
5. "Sonora A Description of the Provinces" by Father Ignaz Pfefferkorn SJ translated by Theodore Treutlein
While the next are not books, they have amazing collections of period documents:
1. DRSW: Arizona State's Desert Relations of the SouthWest. An online repository of documents. Many Jesuit letters, and they can even make you a copy of Father Eusebio Kino's Travel Journal in the original Spanish. Some interesting things there. For some, you may need to be able to translate Colonial Spanish/Jesuit Documents.
For anyone unfamiliar with Spanish Document Translation, I recommend going through a website called spanishpaleographytool.org It will the newbie through three of the most common Spanish Script Types in use during the 15th-18th Centuries. Although it is a great tool, it doesn't cover the most difficult to learn style, called "Chain Writing" or "Chain Script", in which there are no breaks between words. The reader has to understand. Its a bitch.
Another great tool that helped me at first, was a book printed by the University of Texas at Houston in 1951. It is a guide to assist in translating Colonial Spanish Documents.
2. My website's Reference Section. I have provided a crap-ton of historical books on mining, and everything associated, as well as a page of period maps:
That will get anybody started, and give them enough to do for a year or two.
Best of Luck - Mike