Here are some links that deal with Sankt Nikolaustag in Germany:
https://www.youtube.com/watch?v=RoJEqFY5n-o - Das Nikolauslied
http://www.stnicholascenter.org/pages/germany/ - Background information from the St. Nikolaus Center
https://www.youtube.com/watch?v=i3O3_xXbNm4 - A video in German about how Nikolaus is celebrated in Bayern. (German 2 or 3)