The market for Star Trek reference books took off around the time of the release of Star Trek: The Motion Picture. Throughout the 1980s and beyond the original series and its progeny were analyzed, classified, and commented upon by a multitude of authors in various ways.
The Star Trek Compendium by Allan Asherman is one of the earliest and one of the best guides to the original series. It was first published in January 1981. The 1981 edition provides background on TOS, a TOS episode guide, and a chapter covering Star Trek: The Motion Picture. My copy is from the 7th printing and was purchased on 19 June 1985.
A revised and updated "20th Anniversary Edition" of The Star Trek Compendium was released in September 1986. It added coverage of the second and third movie as well as a brief episode guide for the animated series. My copy is from the first printing.
Another revised and updated edition was published in July 1989. Coverage for The Voyage Home and The Final Frontier was added. My copy is from the first printing. There were a few additional editions of this book, but in terms of my purchases I drew the line at three!
A Star Trek Catalog was published in October 1979, presumably in anticipation of the first movie. It includes a short interview with Gene Roddenberry, a look at Star Trek fandom, a chapter dedicated to the actors, a (brief) synopsis of each TOS and TAS episode, and a look at some of the Trek books and merchandise which had been released up until that time. I received this as an early 15th birthday present on 28 September 1983. (Apparently it was on sale for 99 cents!)
This is an interesting book which postulates the development of space travel from the 20th century into the early part of the 23rd. It includes wonderful line art and paintings by Rick Sternbach. It was published in January 1980. My copy is from the first printing and was purchased on 19 April 1984 on sale for $1.99.
The Monsters of Star Trek is a short book which again seems to have been released due to the expected popularity of the first Star Trek film. It classifies some of the aliens that have appeared on the original series (e.g. "energy creatures", "ancient races") and provides some information about them interspersed with recaps of the episodes in which they appeared. It also has some decent b&w stills from TOS as well as a few from ST:TMP. This book was published in January 1980. My copy is from the 2nd printing and was purchased on 3 July 1984.