Conducting an informational interview is a great way to learn about the world of work.
By speaking to individuals who are already working in the fields that interest you, you can get personalized information about a career, organization or job and build your professional network at the same time. Keep in mind that informational interviewing and networking are not about asking for jobs. Your connections may (and often do) lead you to a job opening, but your focus with these activities is on making connections and gathering information, not on asking people if they know about job or internship opportunities.
LinkedIn can be a powerful networking tool. By creating a profile and joining relevant groups, you can connect with alumni and other professionals in the fields that interest you. Search for alumni by going to LinkedIn.