If you want to bet on football, then you have plenty of options. There are not only lots of games you can bet on, there are also lots of different types of wagers you can place. Point spreads and totals are the most popular types, by quite a distance, and many football bettors stick solely to those. This isn't really the ideal approach, as some of the other wagers can be very useful in the right circumstances.
The only real downside to betting basketball point spreads is that the sportsbook charges a vig. While this is a downside, it is to be expected and is no different from placing any other sports bet. Obviously, the sportsbook has to make money somehow because they have to pay employees, pay for their servers or equipment, and pay for their customer service to keep you happy. This really isn't a negative about point spread bets, but just something that you should be aware of.
Overtime and the shoot-out does count for NHL point-spread results in Ontario. Whenever you see a game -0.5 essentially both teams have a spread of -0.5 and your team has to win the game for you to win the bet. Lately there have been more -1.0 / +1.0 NHL spreads in Ontario. If you choose the -1.0 spread and the game goes to overtime you cannot win the bet. You can only push the bet if your team wins in overtime or the shoot-out. Conversely, if you choose the +1.0 spread and the game goes to overtime you cannot lose the bet but will push the bet if your team loses in overtime or the shoot-out.
For each NFL game the oddsmakers set a number of points in which the favored team is favored by. Bettors can then either choose for the favored team to win by more than the number of points set, or bet on the underdogs to lose by less than the number of points they are underdogs by or win the game straight up. For example, the spread could be set on the favored team at 6.5 points. This would mean in order for a bet on the favored team on the spread to win they would need to win by more than 6.5 points (7 or more) in order to win the bet. It also means that a bet on the underdog team would win if the underdogs lost by less than 6.5 points (6 or less) or won the game outright.
The odds listed are a primary way of gauging the play in the game. There are hundreds of mismatches every single year and the leveling of the playing field has been very helpful in resolving that particular problem. With the use of odds, bookies are able to acquire an equal number of wagers on each team, which assures them that they get money regardless of who wins.
The point spread bet is a bet designed to give each team an equal chance of winning a particular game. Obviously, not all teams are equal, so the sports-books have devised a mechanism to even up the teams, and that is by taking points/runs/goals off the team who is favored. The more a team is favored, the more the gambling site will take off them, enough to theoretically make the game a 50/50 chance.