Truncheon books is a publishing house which is first mentioned in episode 8 season 6, when Jess Mariano turns up at Rory's grandparents house to show her the short novel he wrote called The Subsect, the book was published by Truncheon books.

JESS; I didn’t think you’d believe it if I didn’t show it to you in person. [hands her a book] RORY; Oh, color me curious. A book. [reads front the cover] The Subsect. Written by Jess Mariano. [she looks at him] JESS; It’s no misprint. RORY; You wrote a book? JESS; A short novel. RORY; You wrote a book? JESS; And, through a fluke, I got it to these guys that have a small press and they read it. I don’t know if they were high or something, but they decided to publish it. RORY; You wrote a book. JESS; There’s no money in it. They only printed, like, five hundred of them. Believe me, I’m not quitting my day job. RORY; But - you wrote it. You wrote a book. JESS; Yeah, I know, it’s hard to believe. RORY; You sat down and wrote a novel. Jess This is amazing!

The owners/founders of Truncheon books (who are seen) are Chris and Mathew, Jess joins the company later, But you don't actually see Truncheon books until episode 18 season 6, where they host an open house and Jess invites Luke, April and Rory. He is surprised at Luke's appearance and even more so when he meets his cousin. Luke asks Jess to give him a tour

JESS; This is where we work: Truncheon Books. There's usually desks and crap piled up everywhere but we cleaned up for today. Those are the books that we put out. We publish our 'zine once a month, except last August when my partner forgot to pay the printer. We let local artists hang their stuff up without ripping them off on commissions, we do performances over there, and a few of us live upstairs, and that you don't want to see. It's a disaster zone.

In this same episode, in truncheon books, Rory and Jess kiss, but Rory confesses that she is in love with Logan and that she only came because she was angry at Logan for cheating on her. Jess tells her that she can tell Logan that something happened if it will make her feel better. And we never see Truncheon books again...