Mission to Horatius is the first original Star Trek novel published. The dialogue is terrible, the plot is ridiculous, Kirk commits genocide, and a dancing rat is an important character. So don’t read the book, but do read my fun teardown of it.
Gene Roddenberry’s 1964 pitch for his new show is arguably the most important Star Trek document ever. The pitch, usually referred to as Star Trek is…, was designed to sell the show to network executives and it’s an interesting look at Roddenberry’s earliest creative ideas.