The series starts with Galaxy Outlaws, then Astral Prime, then Mercy for Hire, while I recommend reading them in order, you can start with Mercy for Hire and be fine, as I did, but wish I would have started with Galaxy Outlaws to get the back story. Reading them 3, 1, 2 fills in a lot of the jokes I missed in 3, but I wish I would have known ahead of time.
All are fantastic, subject matter is mostly clean with mentions of inebriation/drugs and sex, but no illicit scenes. There is some language, mostly from one character in specific in the beginning and end of this collection
The story is immersive, fun, and totally new. The narration is outstanding, with voices that never leave you wondering who is talking.