Do Your Research :
Learn as much as possible about the company you'll be interviewing with, and know as much about the position as you can. You need to do your homework, too. If the company has retail outlets in your area, visit one. If they produce software products, look them over. Talk to people who know the company, explore the business section of the library to get information about the industry, the company and its management. Look over annual and quarterly reports and check the trade publications for the latest information available. The more you know going in, the more informed and intelligent you will seem.

Prepare a List of Questions to ask them :
It's only natural for you to have some questions about the position for which you are being interviewed. Be ready to ask them. Put together a list of 10-15 questions. You won't likely need to ask every one of them, since much of the information may be covered in the interview process itself. But you should be prepared to find out the specifics, like why the last person left, or what are the daily, weekly, monthly and yearly expectations of the job, or what are the significant challenges you would face in the position.

Practice, Practice, Practice :
Much of what will be asked in your interview will be fairly obvious ahead of time. Practice your answers to tough questions you're likely to be asked. Practice your responses, either alone or with someone you can trust to give you an honest and candid reaction. You need to make an honest assessment of your experience and employment history and be prepared to deal directly with both your strengths and weaknesses.

Dress Professionally :
Make sure your first impression is a good one by looking professional and confident. Even when the corporate culture is more casual, it doesn't hurt to be the best dressed person in the room during an interview. This is the time to be conservative in dress, not trendy or hip. For a man, it's best to wear a dark suit with a white shirt and a contrasting tie, polished shoes and dark socks. For a woman, the best choice is a dark, skirted suit or tailored dress with a matching jacket, with neutral hose and simple pumps. A conservative hair style, with clean, neat fingernails is most appropriate, and makeup and jewelry should be minimal.

Arrive Fashionably Early :
You should be at your destination and have reported to the receptionist well before the interview. Fifteen minutes early is a good rule of thumb. To make sure you don't arrive at the last minute, go over your travel route in advance, and even drive it once to test the route so you are absolutely confident you know how long it will take.

Smile at Everyone :
A pleasant demeanor can go a long way toward making a good impression, and it will probably release a little of the tension for you as well. By the time you arrive for your interview, you will likely have spoken to the receptionist at least twice, and now is the time to reinforce any rapport you have with him or her. In any case, this is your opportunity to put your best face forward. Remember, every person you meet here is a potential co-worker.