I have made the mistake by taking too much time before reading the book itself, and I have only watched the Netflix series. If you are not familiar with '13 Reasons Why', you must be living under a rock, since this was one of the most influential and touching stories you have ever heard. A girl named Hannah took a decision to cut herself to death in her bathroom due to constant bullying, rape and heartbreaking actions that her fellow school members did. She left a box with tapes that each tape represents a reason for her death. The tapes are separated to reasons which are the names of those that harmed her. She asks a good friend to keep the tapes and send them to each one of the harming school members. One of the topics of the tapes was Clay Jensen, which was a good friend of Hannah, and the confusion of him being the tapes makes the story more complicated and interesting.
Although the series was fascinating and touching, in my opinion, the book seems to elevate the series. The book contains many more information that the series doesn't show and the reading of the actual book makes the reader to be swallowed in the story itself. As one that has seen the series before reading the book - Please do yourself a favor and read the book beforehand. The series is extraordinary and great, but the book shows a whole other world of the story itself. As this article is spoiler-free, I will not go into details about what's the difference between the book and the series, yet I highly recommend you to read the book since it shows important things that the show might have missed.
In another topic, the second season has already been announced and being filmed. Make sure to follow the news to know when it comes out, as it probably will tell an aftermath of the tapes and after Clay heard the tapes.