My former students, several of whom were bilingual, felt pretty strongly that Gung Hay Fat Choy was not the proper way of saying Happy New Year, but I no longer have them as consultants, so I’m going to have to go with what the web-at-large says.
Should you need to be reading the best books ever for this holiday (also great choices for my January advanced books for little readers) then you are clearly looking for Grace Lin’s Pacy Lin series!