The Mortal Instruments series has been translated into over 34 languages. You can see a variety of the international covers for the books here.
"New York is the city that never sleeps — but evil spirits, angels, warlocks, faeries and shadow-hunters don't need much rest anyway. The city is home to Cassandra Clare's young-adult debut novel, a cool, pleasingly dark and spicy urban fantasy called City of Bones."
— Kirkus Reviews
"Clare's atmospheric setting is spot-on, informed equally by neo-gothic horror films and the modern fantasy leanings of Neil Gaiman. Werewolves, vampires, angels and fairies all fit in this ambitious milieu. At the core, though, this is a compelling story about family secrets and coming-of-age identity crises. Fans of the smart/chic horror typified by Buffy the Vampire Slayer will instantly fall for this new series."
— Publisher's Weekly