The majority of people who fail at their job will fail in the first 90 days. So take special care to make a good start. Here are areas you need to manage carefully.

1. Assume everything in the interview was wrong.

Don't come to work with a preconception of your job description. You'll be disappointed at best and annoying at worst.

During the interview process, a hiring manager tells you a job description that will make you want to take the job. The description is not likely to be an accurate summary of what your boss really wants you to do. After all, no one says in an interview, “You'll have to pick up pieces when my disorganization gets our team into trouble,” or “As a newcomer, you will take the projects no one else wants, which may or may not be relevant to your interests.”

Also, during your initial meeting, you probably asked your perspective boss about his management style. The answer he gave was really the management style he thinks she *should* be using.

People do not generally say what they want. (This is so true that focus groups have to be run in a way that consumers are not asked directly what they want because they say the wrong thing.) So watch your boss, read nonverbal cues, and understand what is motivating him. Once you really truly understand your boss you will be able to constantly adjust what you’re doing in order to meet his or her needs.

2. Get your goals in writing. And meet them.

Find out what your boss wants you to accomplish in the first 90 days. You need to know how you will be judged during this crucial time. Initiating this discussion shows that you are goal oriented and you want to be part of your boss's agenda. Ask for detailed descriptions and quantified expectations and get them in writing. Even if your boss does not create an official document, do it yourself, in an email — an informal summary of the conversation, but in your mind, treat this as a formal agreement.

Of courses, you must meet these goals, but forget about the phrase “hit the ground running” because you'll slip and fall. If you are running have no time to double check where they're going, and there's no time to make sure you are moving similarly to everyone else. Pace yourself for the first few months so you have a chance to learn how the company operates.

3. Manage your image.

Here are questions you'll hear every day for your first three months: Where were you before this company? How did you get into this business? Where are you from? These are general, fishing-for-information questions. It is an opportunity for you to package yourself to your coworkers.

So get your spiel ready. Only a few people interviewed you; most people in the company know very little about you. Have a short, snappy answer for general, tell-me-about-yourself questions. People are going to make judgments that stick, based on this seemingly casual conversation. So prepare in advance.

Everyone will make a snap judgment about you — this is how people operate. Even good people. We can't help it. If you're lucky, they'll ask you a question. But most people will just take a look. So you have no ramp-up time when it comes to image. You have to look right on the first day. Dress like the other people at your level in the company. Set up your desk to present a crisp, organized image from day one. This means not barren but nothing cutesy.

Your desk and clothes are an expression of your competence, not your personality. Express your true personality at home, with your friends who are not evaluating you during the next 90 days.

People should perceive you as a listener. Ask questions, observe carefully, and meet as many people as you can. Instead of spouting off about how great you are, which only serves to show people that you are insecure, try listening to people, which makes them feel important, and consequently they will like you more. And in those first 90 days, who likes you is what will matter the most.