Michael Personally, I think you could...important things from "past books" are brought up. But those are comments made in passing and not fully explained. In my opinion, to fully experience what came before you should read the other books first.
Heather Jensen Incase someone else sees this: I found the prequels (written after the main series) first. And I can say, having just finished last one -- there is so much great reference to elements of the prequel books. I doubt it seems odd, if you don't know. But, I really enjoyed the straight pour through all in sequence. Your mind doesn't have to reference back and forth so much! Anyway, Greatly Enjoyed. HEJ
Arushi You definitely need to read the first 4 books otherwise this will not make a lot of sense. You can read this short story, https://www.goodreads.com/book/show/2..., if you can't decide whether you want to read this series or not. It is based on the same characters but not connected to the novels.