When in doubt the Standard Catalogue of World Coins or the Standard Catalogue of World Paper Money offer fairly complete lists of almost everything. Those notes were printed in 1967 as part of the celebrations of the centennial of confederation. Many were hoarded as souvenirs and they can be bought for just a couple of dollars. They are worth a bit more than face value, depending on the price of silver. If coins are in good condition, the collectors value may be even higher.
Mistakes do happen, and some get past quality control.
Most error coins are worth a small premium over face value, although some spectacular errors can be worth hundreds of dollars to the right collector. Every show is different, but most of the time you will see a room full of dealers and collectors, and possibly some displays of public information or exhibits of collections. It is excellent place to compare prices, buy or sell coins, or just look at a lot of cool stuff. Go there with your eyes and ears open, don't be afraid to ask questions, and you can't help but learn something. There may be a few.