The first thing that you need to think about is what the internship exactly covers. Remember that an internship is something that is meant to help you get real world experience and if you are going to be spending time doing work for minimal to no pay at all, you should be getting something good out of it. Read the internship material carefully and make sure that you speak to anyone that you know has been on the internship in the past. For instance, are you actually going to get work that is related to your field or are you going to spend the summer sitting in the back room handling invoicing or other menial tasks? Even the basic things can give you a worm's eye view of the office, but also think about things like the skills that you will be able to pick up.
Another thing that you should consider when you are thinking about getting a good internship is what kind of supervisor is best for you. The person who is handling the internship program and who is going to be supervising you over what might be a time that stretches anywhere from two weeks to three months to even a year can make a huge difference in the experience. Are they genuinely interested in making the internship a valuable one for both you and the company? Are they going to be interested in how you can move forward and are they looking for prospective employees? What is their working style and how many interns are they going to supervise?
The more time you spend thinking about your internship, the better your experience is really going to be. There are many people out there who are looking for an internship, so keep in mind the fact that you need to make sure that yours is integrated into the work that you want to do. Unless your internship is relevant and unless it is run in a competent fashion, you may end up wasting your time and providing free labor to a firm that has nothing to do with your needs.
This can make all the difference in the world, so take a moment and get the results that you are after. The more research and the more information that you have, the better off you will be!