This article is not going to tell you how to train your dog or be a good dog owner. But it will focus on the specific challenges in owning a rat terrier and how you'll need to adapt to a "rattie" differently than you would other dog breeds.
Instructions
Quick But Sensitive Learner. Rat Terriers provide a unique challenge. They have the stubbornness of most terriers (who were bred to take bites from vermin and not quit). But they have the sensitivity of an Italian Greyhound in their genetics. As a result, this is not a breed that responds well to physical correction. Ratties learn quickly and learn best when the training is positive and based on operant conditioning. Choke chains, swatting with a role of paper, even repeated "No!"s are especially ineffective with this breed of dog. Behavior shaping is also an ideal way to train rat terriers as this is both positive but challenging mentally.
Learn How to Focus. While Rat Terriers are generally very smart and perceptive dogs, they have some focus issues hard-wired in. They have the nose/scent ability of a beagle so walking a Rat Terrier can be especially challenging as every step they discover a new amazing smell worth exploring. But they also have sight hound in their genetic background. Sight hounds were bred to notice small movements that most dogs can't see or don't notice and react strongly to it. So a Rattie on a walk is a dog with especially perceptive eyesight, a fantastic nose and strong prey drive. It doesn't mean that a Rat Terrier can't focus, it just means that it will take work before you have a dog that doesn't pull on the leash during a walk. When your Rattie pulls, it's not about being the alpha or being out of control. Instead, it's like bringing a hungry child into a candy shop. A Rat Terrier outdoors sees and smells so many things that there are terrific temptations. It will take training to build the focus and control. And remember, Ratties respond best to positive training. Rather than reprimanding for pulling on the lead, it's more effective to reward for focus and loose-leash walking. Doing lots of training around tricks is a great way to build focus with your Rat Terrier. Not only are Ratties good at tricks (quick, strong, agile, smart) but this type of training builds focus.
Coping With Alarm-Barking. Rat Terriers are a bit schizophrenic when it comes to barking. For the most part, Ratties don't bark. They might vocalize a series of weird sounds but they're relatively quiet dogs. Until someone comes to the door or walks in front of the house. At which point most Rat Terriers unleash a barrage of frantic barking. Most of the "stop barking" methods (can of coins, squirt can, shock collar) will fail totally with this situation. That's because the Rattie isn't barking for enjoyment. Instead, this is barking as an alarm by a dog that's worried. Ironically, that same Rat Terrier could pass that same stranger on the street and not even glance at the person. But if some one or some thing approaches the sacred home turf, the Rat Terrier will become frantic at sounding the alarm. Trying to punish the alarm barking usually makes it worse (because the real problem isn't the barking--the barking is just a manifestation of the concern the Rattie feels). The best approaches with this situation are to train an alternative behavior (like running to a crate, going into a down-stay) and acknowledging the barking (so the Rattie feels less alarmed and quiets down). In this situation (alarm barking), getting angry or yelling at your Rat Terrier will usually make things worse (because the dog is alarmed and your response just increases the anxiety level). Leslie McDevitt's book "Control Unleashed" has a great game called "look at that" that is ideal for dealing with alarm barking. Remember, to you it may seem like the problem is the barking. But the barking is just a manifestation of your Ratties' alarm--deal with that concern about the stranger coming to the door and the barking will disappear.
Bonding With People. Except for a few breeds, all dogs like to be around people. But Rat Terriers in particular are people-focused. Rat Terriers generally choose human company over dog company. If you're sitting on the sofa, your Rat Terrier will want to get up with you. And when you go to bed, your Rat Terrier will want to get under the covers and lay down near your feet (no, it doesn't smother--don't ask me how, it just doesn't). If you own a Rat Terrier, be prepared for a dog that will prefer to follow you around the house (rather than find a cozy spot and take naps).
Small Dog--What Small Dog? There are a couple of breeds of dogs (Toy Fox Terriers are another) that don't know their own size. Rat Terriers can easily get into trouble not because they're trouble-makers. But because they don't regard bigger dogs as, well, bigger. So they're not intimidated by a bigger dog and tend not to fear bigger dogs. As a result, they can accidently stir things up at times because another small dog might back away or steer clear of a larger dog that a Rat Terrier will take the attitude of "I should saunter over and say 'hello'--maybe he'll friendly and there's nothing to fear here anyway!" They are generally not a very fearful breed. So early socialization and playtime with a range of other dogs is important so your Rattie starts to learn to avoid an early negative experience with a much bigger dog who may not want to share food or toys.
Temperature and Climate Concerns. This is a breed of dog that has a very short coat and almost no hair on the belly. So you'll need a coat for your Rat Terrier in cool (let alone cold) weather. Conversely, it handles heat much better than a bigger or heavier coated dog. Also, many rat terriers hate water. Not all, but probably a majority of Ratties will have issues going out in even mild rain (while other breeds will go romp or chase squirrels).