Decide on the concentration you want to pursue in graduate school. Consider your undergraduate track of study, other academic subjects that you may have found interesting, internship experience that dealt with a particular field, or recommendations of friends and family members who may be able to help you consider program options. This will narrow down your list of schools.
Speak to past and present professors and any other school faculty who are able to assess your work and make recommendations on the programs you might pursue. Professors will often be able to put you in touch with integral contacts at various schools, and these connections can help with your chances of admission.
Consult library resources, such as graduate school guidebooks. Libraries have a vast amount of information about PhD and other graduate programs. Carefully look for your particular concentration.
Write down a list of schools you're interested in based on conversations with faculty and your personal research. Write each school's entrance requirements and academic specialties so that you can assess the information later.
Visit websites such as princetonreview.com and usnews.com. Both websites offer information about schools around the country. The princetonreview.com lists admission statistics, tuition costs and student perspectives on each program. Usnews.com ranks each school from highest to lowest based on reputation, endowment and program excellence.
Consult your list of institutions and follow up on your additional research to find the best PhD programs for your course of study. Apply to as many of the programs on your list as you can to increase your school options.