Lucasfilm and Del Rey have announced a new novel STAR WARS: MASTER AND APPRENTICE written by Claudia Gray (LOST STARS). The novel will star Qui-Gon Jinn and Obi-Wan Kenobi. Other than a 2019 release date, I have no further information, unfortunately. I will keep you all updated as I get more info.
I would love if this novel covered Qui-Gon Jinn and Obi-Wan's one year mission on Mandalore, something that is mentioned in the television series STAR WARS: THE CLONE WARS. I'm really happy to year we are getting some Prequel era content. May the Force be with you.
UPDATE: Lucasfilm's executive editor, Jennifer Heddle, has confirmed in a Twitter post that MASTER AND APPRENTICE will be released February 2019. View her tweet here.