(written from a Production point of view)
Which Way Books were a series of solo-adventure game books published by the Pocket Books imprint Archway Books. Each book requires the reader to not read the book in page order. Rather, the last few lines on each page give the reader a set of choices (between one and three choices) of which way they want the storyline to go. The reader then turns to the directed page to continue the story, where they are presented more choices that direct them to other pages in the book, eventually leading to the story's end, which can be a happy ending, or a rather sudden BAD ending.
Of the 24 volumes published, two focused on Star Trek-related adventures. In each book, you are a Starfleet ensign, newly-assigned to the USS Enterprise. Each book gives you three possible starting storylines, which follow to a multitude of possible endings.
The first volume, Voyage to Adventure was published as Volume #15 in 1984. It sold well enough that it was reprinted in 1986 (with updated cover art) alongside a second volume, #24, Phaser Fight, the last of the books in this series.