The books are really good, but TBH it's not the end of the world if you don't catch them right away. For its milieu, the show is even better than the books are for theirs. There is the usual extra detail, deeper insight, and unlimited budget of the books, but the casting and performances really elevate the show, and a few characters (Drummer, Ashford, and Errinwright come to mind) come out of the adaptation process really well. People go on about how great it was that the authors were involved in the show, and that's true, but critically, they understood that a different medium needs slightly different things.

I'm not an audiobook person, but if you are, I understand the ones for The Expanse are absolutely top-notch.