Internships provide opportunities to not only learn practical skills, but also offer chances to examine a work culture and the different styles that come along with it: how to work in a team or alone, how to dress, or how to work under deadline pressure. Ask yourself what you would like to personally gain from the experience and what company would best suit you. If you are uncertain about what approach best suits you, feel free to contact an undergraduate advisor.
When you are ready to apply for internship positions, be sure to do so well in advance since deadlines can be early. Getting a head start will not only give you enough time to get organized, but it could also give you a leg up when trying to secure a competitive internship.