Leia: Princess of Alderaan by Claudia Gray
If you've ever wondered what Leia's life might have been like on Alderaan as a 16-year old princess training to lead her planet as well as for her position in the senate, this is the book for you. In this book we are introduced to a Leia who hasn't gone to war yet or suffered any major loss in her life, is accompanied by her parents, and has her first kiss. Folks who have watched The Last Jedi will also recognize a few people (like Amilyn Holdo) and places (like Crait) of significance to this story as Leia starts to rise as the leader and rebel she becomes in Episode IV and beyond. This is a great read for anyone who enjoys a strong female protagonist, character exposition, and just a good story in general. I highly recommend it on audio.
Star Wars: Bloodline by Claudia Gray
In contrast to LPOA, Leia is a bit older in Bloodline. This book takes place several years before the events of Episode VII, and it comprises the events leading up to Leia's ultimate decision to leave the government and become the resistance general she is in the latest films. A terrorist attack is carried out in the senate building, the government is divided between two parties that care more about opposing each other than actually making anything happen, and amid all this, Leia gets a taste of action again when she gets involved in an investigation of a crime cartel. This book also expresses the moment when the galaxy finds out that Leia is Darth Vader's daughter, something she's kept secret all this time because she simply can't reconcile it. I also highly recommend this on audio, and I recommend it for lovers of action, political intrigue, and just a little bit of nostalgia.