Research thoroughly about the company you are going for an interview. Find out the business of the company, what are the skills they are looking for, how you can contribute to the company's growth, company's prospects, your growth prospects etc. etc. Use your network to find out about the company, talk to career consultants to find out, look out on the internet.
If company has a web presence, visit their web site and note down all the factors, which will help you arrive at a decision. Make a list of questions you may have come up. These can be asked and get answered at the time of interview.