1. DON’T BE LATE TO YOUR JOB INTERVIEW, BUT DON’T BE TOO EARLY

Don't be late -make sure you have the company's telephone number so you can call if you are unavoidably delayed.

 Just as important, don't be too early. If you arrive 20-30 minutes before your due time and are waiting in reception, your interviewer will feel pressured to see you before your allotted time and will likely rush through current commitments to avoid feeling guilty about keeping you waiting.  This is not the best frame of mind in which to meet - it immediately puts you at a disadvantage.
So, 5 minutes early is perfect, 10 minutes is acceptable but no earlier.  If you do have time to kill, park up somewhere and go through the job description and your questions one last time.

2. PREPARATION - Find out as much as you can about the company – For some good sources of information, click on Preparation