Quote Originally Posted by LL2
1. Wear a suit and tie as mentioned before.
2. Get to know as much about the company and the position as possible
3. If you can find out anything about the individual(s) you will be interview with. Small talk at the beginning is important.
4. I'm not a programmer, but a friend of mine is and he brought samples of his work with him.
5. Study like you would for a test. They are likely to test or quiz you on your technical knowledge.
6. Most importantly maintain your poise and never admit you are nervous (even though you will be).

Let us know how it goes!
These are all good tips. I support them and encourage you to follow them.

Also:

1. Arrive 5-10 minutes early. DO NOT BE LATE! It is a bad sign to your prospective employers if you show up late.

2. As an earlier poster stated, maintain good eye contact.

3. Besides the suit, make sure your shoes are polished. Some employers put stock on polished shoes as a first impression.

4. Following the interview, shake hands in a friendly, yet firm manner, and thank him(them) for his time in meeting with you.

5. Upon arrival at home, immediately send a neat, mistake-free letter thanking your interviewer for the time to meet with him. End the letter with "I look forward to hearing from you."