I'd like to recommend this book to both of my semi-adult children. As with Looking for Alaska, Green has created a powerful portrait of the tensions and vulnerabilities of adolescents approaching early adulthood. In this novel, again with a male protagonist, plot tension is maintained throughout the book. I won't spoil the ending.
There are many opportunities for interdisciplinary extensions in this book: cartography, poetry (especially Whitman & Plath), music, Florida, and New York. I would recommend this for students 9th grade and above.