At home, at lunch, and on TwitterTwitter reviews, everyone seems to be talking about the Preakness, one of most prestigious thoroughbred horse races around. They’re talking about the lone female horse in the race (Rachel Alexandra) or the underdog winner of the Kentucky Derby (Mine That Bird). Now you’re even more confused than ever. If you’re interested in learning more about horse racing, or at least being able to understand what people are actually talking about, there are a couple of good ways to use the Web to get yourself up to speed. By the time you’re done with this list, you’ll know more about “The Run for the Black-Eyed Susans” than anyone else you know.