This is a new release and it looks like the start of a new series!  To properly understand this book, you should have read the Percy Jackson series. In this book, Percy and Annabeth plan to graduate high school and go to college in New Rome. However, Percy soon learns from his college counsellor that he must get three letters of recommendation from three gods to get into college. To get these letters, he has to go on three new quests. This book is about the first quest, for the cupbearer of the gods, Ganymede. Percy has to retrieve his golden chalice before he faces total humiliation in front of Zeus at the next feast, where he will be asked to serve them nectar. The cup can also turn any mortal who drinks from it immortal, so retrieving it is crucial for Percy, Annabeth and Grover before that power is used. 

I really liked the character development. I like how Percy matures and also in the way he views his relationships with Annabeth, his mom and his stepfather. I didn't see any of this in Grover's character and his role hasn't changed in any significant way since the first book of the Percy Jackson series. I suggest reading Rick Riordan’s books related to Greek Mythology in the following order- The Percy Jackson series, The Heroes of Olympus series, The Chalice of The Gods, The Trials of Apollo, The Sun and the Star.

All in all I loved this book and I can't wait to read the rest of this series which hopefully comes out soon!