There are several options open to you there. The answer depends on where you'd like to go with your degree. A minor in IT or Information Systems can be helpful in many Computer Science related fields as these can help to give you a better understanding of the overall technology stack beyond the programming and algorithmic techniques you will learn in your CS classes. A mathematics minor may be helpful if you are looking to get into more of a data analyst role, and you will likely already be taking most of the prerequisites for this during your normal curriculum. Finally, a business or communications minor could be helpful as well to help you better communicate with and understand your less technical peers at your future employer.