If you are a college graduate, your alumni association can be a huge asset in gathering information. Most have networks of grads who have offered to be resources for other alumni and can offer a wealth of information on a wide variety of fields.
Reading trade publications can help you learn about the issues and trends within an industry. In addition, periodicals such as The Wall Street Journal and the New York Times often feature profiles of successful professionals in fields you may be considering.
Attending association meetings can give you the opportunity to meet people in a new field and hear about opportunities and hot topics.
Internet bulletin boards and chat groups are another effective way to find out information from people in different fields and industries. Some Web sites such as ExpertCentral.com allow you to post a question and receive answers from experts in various disciplines.