My mother grew up in a North Dakota German family that celebrated 6 December and St. Nicholas Day. The children would hang up a sock the night before, and in the morning there might be fruit and nuts.
One outstanding memory for Mom was when some of the neighbors got together to stage a visit from St. Nick himself. It is not clear to me whether it was on the eve of the feast or the feast itself. The family was at home minding their business, when the door suddenly flew open and The Saint Himself threw nuts and candy into the room, departing quickly with well-wishes and blessings.
According to the web site of the St. Nicholas of Myra Catholic Church in North Dighton, Massachusetts (and what could get more official than that?!):
St. Nicholas was probably a native of Patara in Lycia, Asia Minor. There are far more legends about his miraculous good deeds than there are clear details about his life.
This much is known for sure:
Nicholas was first a monk in the monastery of Holy Zion near Myra. Eventually he was named the Abbot by the Archbishop, its founder. When the See of Myra, the capital of Lycia, fell vacant, St. Nicholas was appointed Archbishop. It is said that he suffered for the Faith under Diocletian, and that he was present at the Council of Nicea as an opponent of Arianism. His death occurred at Myra, in the year 342.
The characteristic virtue of St. Nicholas appears to have been his love and charity for the poor. Because of this and of the many legends of his works, St. Nicholas is regarded as the special patron of children. The Emperor Justinian built a church in his honor at Constantinople in the suburb of Blacharnae, about the year 340.
He has always been honored with great veneration in the Latin and Greek Churches. The Russian Church seems to honor him more than any other saint after the Apostles.