Las Vegas is the only place in the U.S. where gamblers can legally bet on sports. But that doesn't mean you can place a wager with any old bookie. In order for the bet to be legitimate, it must be placed with a Nevada Sports Books licensed organization, which of course can now be found in nearly every casino, from the Palm and the Wynn to Arizona Charlie's and Whiskey Pete's.

Odds are placed on each game or match to give bettors an idea of who the favorite is to win. Most Sin City sports books get their odds from Las Vegas Sports Consultants, Inc., the largest odds making company in the world. Odds can be influenced by many factors including player injuries and current wagers (in other words, they don't just make them up). There are two main types of odds to look for: point spreads and money lines. Point spreads are generally used for football and basketball games. The spread dictates how many points the odds maker thinks the favored team will win by. For example, if the Lakers are favored to beat the Knicks by a point spread of seven, and you've bet on the Lakers, they have to win by more than 7 points for you to win the bet. The odds notation will look like this: Lakers -7 (because they're favored) and Knicks 7. But if you've bet on the Knicks, you'll win if the Knicks win by any point total or the Lakers don't win by more than 7 points. This type of bet typically pays $100 for every $110 wagered.

Money line wagers, on the other hand, are typically placed on baseball. Instead of points, the money line uses—what else?—a dollar value to calculate your winnings (or losings). Say the Cubs are favored to win, notated by -130. This means you have to wager $130 to win $100. But if, instead, they were the underdogs (notated by 130), you would win $130 for every $100 you wager. Note that the Cubs do not have to win by any particular point value. Get it? Good.