Welcome! As you can easily imagine, internship is a very effective way to get real-life experience, esp. in connection to what you do at the College. At some prestigious financial firm, typically 80% of the summer interns return to the firm as permanent employees. So, if you have already identified companies you want to work for, applying for a summer internship there would make a perfect sense. However, just having a desire is not enough. You will need to draw up a successful plan to get the internship, which can be a challenge. My first advice would be to act early. Get familiarized with the resources available at Career Services and subscribe to the CS internship mail list (from our internship site). Also talk to other students who have already experienced internship.
Even if you do not have a clear idea what to do upon graduation, you should start early. In fact, you will need more time to find out what you want to do, before applying for an internship/job. Again, Career Services is the place to start with. You may also consider more than one internship experiences so that you can compare them.
In our department, internship and mentored research are considered as capstone courses. As a result, there are requirements shared by these two distinct types of experience, e.g., paper writing and presentation. Some of you might feel that the posted internship process is rather complicated and tedious. However, the process is supposed to reflect real-life situations where various skills are required. According to informal feedback from the employers, the learning goals listed on our internship evaluation form are close to the qualities they seek in their employees. If you cannot deal with a process like this, you will need to recharge yourself and develop the basic skills necessary to undertake internship successfully.
Once you gain confidence in your ability to accomplish your goals (including the ones you identify yourself for your own internship experience), you should be able to apply the skills to a diverse range of professional and academic activities. Your life will be more like a series of complex problem-solving tasks, rather than a series of information retrieval (cf. the movie "Brazil"; no offense to Prof. Martinovic's course) or test taking.