While I basically read every adult novel of Star Wars as it comes out, I skip over most of the young adult or early reader books. Generally this has served me well, but occasionally there's a Star Wars young adult book worth my time. It turns out Before the Awakening is one of those.
It's a book broken into three parts, one for each main character in the movie.
Finn's story is all about his stormtrooper training, relationships with his squad, interactions with Captain Phasma, and his first deployment. It's really good backstory.
Rey's story covers a few months of her scavenger. It explains where her mechanical and piloting skills come from as well as giving some more information on how she views the world.
Poe's story ties in most directly with it basically leading right up to the point where the movie starts. We learn about Poe's skills a bit but mostly his story fleshes out the relationship between the New Republic, the New Republic Navy, Leia, and the Resistance. I feel like I have such a better understanding of the political situation in the galaxy after reading his story.
Before the Awakening is a quick read but it definitely adds some depth to The Force Awakens. I think it's worth your time.