Here is the classic Timesavers book with lots of resources for teaching holidays. also this reference book for holidays. This Let's Talk holiday ppt is great for full class use. Or print off the main slide and use as a hand out. Like you can with all the Let's Talk ppts. (File - Print Preview - Print).
Don't forget the Gif Lingua Holiday books! or Holidays Around The World reader.
Share your holiday related resources here!
I'll be posting up more here in the near future!
Here is a nice reader that's free online. Chalk full of materials, many of them Canadian holiday oriented.