If you havent visited your career services office on campus, do take time long before graduation to do so.
Introduce yourself to the staff, let them know you will be stopping in frequently (daily if you are in your last year) and utilize their knowledge. They can assist you in all your job search (and research) needs. Before you get your heart set on a major, you may want to discuss with the career services staff the latest information available regarding your choices. You can also try a career quiz to help determine a career based on your personality and interests. If your first choice seems to have a negative 5 to 10 year projection, its best to research your second and third choices, giving you more options. Keep your focus on what transpires as you go through school, monitoring how your field of interest is fairing. Be sure to watch the unemployment rate in the area you wish to eventually settle down in after graduation. Should that unemployment rate remain high, its wise to discuss with the career services staff other locations they might suggest you consider, and then research.