Sometimes a picture is worth one thousand words and that's the case with a graphic Toyota has produced to promote its certified pre-owned program.

Called the "12 Things You Didn't Know About Car Buying," it outlines statistics behind new and used car shopping that could factor your next purchase of a used car.

The first factoid claims people spend one to three months considering the purchase of a new car.

That's kind of a wide timeline, but it's also helpful information for a used car buyer. It demonstrates most people have patience when buying and you should, too. Never feel compelled to buy the first used car you see. Take your time, take a deep breath, and if the used car is sold before you can pull the trigger, there are lots more out there.

The average amount a buyer spends online doing research before buying a car is 19 hours. The best buyer is a prepared buyer. Really research online any used car you are considering before purchase. Go to Cars.About.Com to read reviews on the car when it was new. (Also go to SUVs.About.com, which also includes minivans, is another good site, as well as Trucks.About.com, which, as its name suggests, covers pickups.)

Here's an important lesson for used car dealers: build a good Internet sales department. According to the Toyota information, 53% of people prefer to have their first dealership interaction online. It's how I bought my last car and it's what I tell anybody who asks.

Start the car buying process online.

Of course, if you are shopping for a used car online, (and there are lots of online used car options like Costco) consider creating an email account that's just for the used car buying. That way you can shut it off when you have completed the used car buying process. It's a step I wish I had taken five years ago to avoid getting contacted by dealerships five years later!

By the way, 12% of buyers likely trust the opinion of a dealer's website; 30% likely trust the opinion of a manufacturer's website; and, 37% likely trust the opinion of independent research. Let me say something about the last category. Not all independent research is the same. Check the writer's credentials before blindly taking his or her word for gospel.

Used car sellers should also embrace this stat: 25% of car buyers find the process to be fun and interesting, which means 75% don't. When putting your classified ad make sure there are lots of pictures and details about your used car. Don't be like this sign I saw by the roadside in Virginia: "Convertible For Sale. Low Miles. Good Price. Call …" That sign was so sparse in its details it neglected to mention what kind of convertible was being sold. While the sign was interesting, it was for all the wrong reasons.

Also, don't be surprise if a buyer seems really interested in your used car and then never calls back with an offer. You're not alone. The average car buyer looks at five cars at a time.

This statistic is really amazing. According to the Toyota research, 52% of buyers don't have a specific model in mind prior to arriving at a dealership. Toyota says that is based on a single poll but it seems to run counter-intuitive to the previous fact that 80% of people used the Internet for research prior to buying their car. What were a lot of them researching if not a specific model?

Assuming the 80% statistic is correct that means one-in-five consumers may not have a specific model in mind when first approaching a dealership. (The percentages, of course, could be skewed because not all used car transactions take place at dealerships.) Those 20% are susceptible to being taken advantage of by less than scrupulous dealership employees.

Always know the make and model of the used car you want to buy when walking into a dealership. You may find the model you saw advertised is no longer available, which is not that uncommon when dealerships want to entice people onto the floor (or have internet sales departments that don't update their websites regularly). Not knowing a particular model is going to lead to you being upsold.

Preparation is the key to getting the best used car deal. Keep the research from Toyota in mind when used car shopping to help you avoid the mistakes other make when buying a used car. Just a little bit of forethought could save you hundreds, if not thousands, of dollars.