Never paid much attention to the Tour de France before? Well, here's some basic information to help you get started. See Outdoor Life Network on your cable system or any of the various websites that cover the tour in-depth.
Race setup: The Tour de France is a 3-week long race mostly through France but also in the surrounding countries of Belgium, Spain, and Switzerland. Each day's race is called a stage. A stage may be a mountainous up-and-down affair stretching 200 km, an invidivual time-trial (where riders don't ride with one another, but are started at different times and race against the clock), or a team time-trial (same as individual time-trial except that a whole team races together and all riders' times are factored in.)
Teams: The Tour is not an individual event in the sense that each person is out there riding for himself. Each rider belongs to a team and has a specific role on that team. Only one member of a team is vying for the top position in the race and all other team members are there to support that one rider. For instance: Lance Armstrong is the top rider of the U.S. Postal Service team and he doesn't want to weigh himself down carrying bottles of water or waste time going back and forth from the team car to the front of the race. So, his teammates go back and forth and bring him water. Another example is when a group of racers pulls ahead of the peloton (this is the largest group of riders at any given time) and there is someone in that breakaway pack who poses a threat to someone high in the rankings. Then the teammates of those higher-ranking riders will attempt to "pull in" the breakaway pack so that they can't gain time on the leaders and so that the leaders don't have to use up their steam to reign them in.
Yellow Jersey: The maillot jaune (yellow jersey) is worn by the rider who is currently in the overall lead. Each day there is a stage winner. Often the stage winner is not the overall leader, so the yellow jersey does not go to each day's winner most of the time. The times and points from each day are combined to determine the overall ranking. There is also a green jersey for the rider with the most points (based on finishing first at selected "sprint" locations during each stage), a polka-dot jersey for the rider with the most climbing points, and a white jersey which is analogous to the yellow jersey but it is contested only by riders under 25 years old.
There is so much to know about the Tour de France and so many ways to enjoy watching it. It is full of high-speed strategy, dependence on team, unpredictable weather, and amazing levels of endurance. However much attention you pay to the Tour this year, I hope that you enjoy it.