Star Wars: The Last Jedi hints at the location of the Jedi books even before they can be spotted later on aboard the Millennium Falcon.
However, it was said in The Force Awakens that he had been in search of the first Jedi temple and when newcomer Rey finds Luke on Ach-to in The Last Jedi, we know he found it.
Throughout the course of The Last Jedi, Rey attempts to convince Luke to teach her in the ways of the Force, and he finally relents, showing her the temple and the ancient Jedi texts.
Related: What Does The Last Jedi Reveal About Rey’s Parents?