Statistics are useful in many ways; in addition to enhancing one's understanding of a subject, they can provide persuasive evidence for a point of view. You can find statistics on just about any topic, but it helps to first ask yourself some key questions about the data you're seeking:
In other words, It's helpful to consider where you might reasonably expect to find the data - this can save you hours of fruitless searching.
For current American statistics from the Federal Reserve Bank of St. Louis.
To look for other data or statistical publications, google using quotation marks around your phrase and site:.gc.ca. E.g. "international trade" site:.gc.ca
Here's a flash video that will show you the steps for navigating the Government of Canada Publications' website.