(written from a Production point of view)
Star Trek was published in several in-universe print forms by Ballantine Books in the 1970s in the USA, under license from Paramount Pictures, and was preceded in 1968 by the single production POV The Making of Star Trek reference book, which attained a legendary status as such by becoming the very first one of its kind.
Summary[]
Ballantine Books was a publisher given license to produce a series of novelizations and other media tie-ins based on Star Trek, starting in the 1970s and continuing until the license was exclusively awarded to Pocket Books in 1979. This was not an exclusive license, as comics, new stories and episode adaptations were published concurrently by Gold Key Comics and Bantam Books. Interestingly, both Bantam and Ballantine are currently owned by Random House. In the UK, Corgi Books published local editions of both the Ballantine TAS novelizations, and the Bantam TOS line, in the '70s.