Learning to find and use statistics can be tough. Here are a few things to keep in mind:
National and even regional statistics on things like demographics are often going to be old. The census is only taken once every ten years, and smaller surveys may appear every three or five years. You'll find the most recent statistics in articles.
Statistics are typically gathered from government sources, from companies like news agencies, or by academic researchers. Keep in mind who is garthering statistics and why when you consider using them. What biases might be involved?
Many statistic sites will allow you to download tables and then manipulate them using software like excel. This can make it easy to find percentages and do other math. Can't figure out how? Ask a librarian!