Infinite Yield Forex is one of my favorite blogs about finance. It's also one of the most useful. Here's the concept. Joel Rensink opened a small $500 account at Oanda during December of 2007. His goal is to take this to $100,000 in less than ten years. His blog is a chronicle of that journey. It's amazing. He's doing this in real time. Even better, he shares his systems and makes them available by email, so you can take the same trades. It's a great informal test of the random walk hypothesis. Don't be surprised if that blog turns you into a random walk skeptic.
Joel Rensink is an experienced trader who gives some great advice and interesting market observation along the way. I can't think of a better introduction to trading. Just following the blog is instructive. Opening a small account at a firm like Oanda is even more educational($100 is fine and can be better than a practice account that tends to keep you emotionally isolated from your performance). It teaches you how to consistently take the trades and deal with the inevitable drawdowns and their emotional consequences. Not everyone can handle this and many will be better off doing something else. There are financial rewards, however, for those who have the patience and the persistence to consistently follow a system with a verifiable mathematical edge.