What type of jacket would be best for me?

It doesn't really snow in December. It happens, but not often. The best advice is to wear layers (long sleeve shirts, thermal tops or sweaters) instead of relying solely on a big heavy coat. One of those North Face brand insulated jackets or coats work well in December. It does get windy, so if a cold breeze frightens you, make sure you bring a hat, scarf and gloves. Waterproof boots and thermal bottoms are probably overkill in December.