Two weeks from now will usher the Year of the Water Dragon. As such I invite my fellow Glitchen to wear a Dragon outfit around January 23.
Also, here are the normal greetings on the the Chinese New Year:
● Gong Xi Fa Cai (Mandarin)
● Gong Hei Fat Choy (Cantonese)
...which both translates as "Wishing you prosperity in the coming year."
The proper way to reply is to greet them the same way, unless you're close colleagues or friends in which case you can reply with Hong Bao Na Lai.
The literal way of saying Happy New Year is Xin Nian Kuai Le, but it's not really used that much.