We've got two main characters, Hazel and Augustus, both cancer survivors, one surviving at a higher level than the other. They meet in a cancer support group and are immediately drawn together. They are typical John Green characters: smart, funny, sarcastic. You will love them upon first reading.
The secondary characters are pretty fantastic as well. Issac, yet another cancer survivor who has just lost his last eye. Peter Van Houton, the reclusive author of Hazel's favorite book (i loved him even when I was sneering at him). The various sets of parents who are all refreshingly functioning and supportive.
There is plenty of gallows humor, I imagine continually dealing with your own mortality helps you develop coping skills that if you are lucky include humor and humility. Also in typical John Green fashion, this is not a book dumbed down for the masses. This is for the kids who are sharp, who are looking for answers, who don't mind thinking about things and figuring them out.
I read this in as close to one sitting as is possible for me. It took under 24 hours and my eyes leaked the entire way through (they dripped even when I was laughing out loud). It is a book that will hit your emotional core early and often and you'll be so glad you picked it up.
Book Source = Library