Welcome to the forums LeelatheCute,
Like Brent mentioned the Bank of Canada website provides a lot in invaluable information on how to spot current series counterfeits.
However from what you've mentioned about being a forex broker you're probably looking for reference material that covers nearly all the different currencies (major) that exists. That being said I know and have seen a catalogue-like book that is issued by American Express that some banks use as a reference of what genuine notes (along with some security features) should look like or if they are still redeemable. I've asked to flip through it and I was surprised to notice that it not only shows you current series currency but also examples of older series ones.
I have no clue how to acquire one of these books, but I'm sure Amex would be more than happy to take some of your money in exchange for a copy.
Good luck!
