Here are some very useful sentences to use during Christmas time and New Year. Listen to their pronunciation in the audio.

¡Feliz Navidad! – Merry Christmas!
¿Qué le pediste a San Nicolás? – What did you ask Santa?
¿San Nicolás te trajo todo lo que pediste? – Did Santa Claus bring you everything you asked for?
¡Feliz Año Nuevo! – Happy New Year!
¡Harta plata en el bolsillo! – Lots of money for you!
¡Mucho amor, mucha paz y salud! – May you have love, peace and health!

Santa Claus has more than one name in Spanish: Papá Noel, San Nicolás, Santa Claus and Viejo Pascuero. December 24th is called La Noche Buena in Spanish-speaking countries

Now some more expressions related to Christmas and New Year.

armar el árbol – put up the Christmas tree
cantar músicas navideñas (villancicos) – sing Christmas carols
comprar regalos – buy gifts
desear feliz año nuevo – wish someone a happy new year
esperar las doce de la noche – wait until midnight
hacer la cena de Navidad – have Christmas dinner
hacer pedidos / promesas de año nuevo – make New Year’s resolutions
hacer regalos – give presents
ir a la misa del gallo – go to midnight mass
recibir regalos – get presents
reunirse con la familia – get together with your family
reunirse con los amigos – get together with your friends
tomar champán – drink champagne
trasnochar – stay out all night

You can read more about Christmas clicking here.

Nos vemos prontito.