cassielin - I need your tips!

Hi guys,

I was invited to a private party for christmas this morning! They are an American couple who live in Fuzhou(my location) and teach spoken English in our college. I am wondering what kind of manners are considered nice and what kind of gifts may be appropriate. I need your tips and advices. Thank you so much!

Ps:

I am really looking forward to it! It will be my first time to visit a foreign friend's home！

Cassie