Create a list of possible fields in which you would like to obtain your Ph.D. You do not have to obtain a degree in your undergraduate field of study, although it can be helpful. Many Ph.D. candidates pursue undergraduate studies in one field and pursue a Ph.D. in a complementary field. Narrow down your list of fields to a few that are interrelated. For instance, history, biblical studies and anthropology are all related fields that would allow you to study one while incorporating the insights from each of the others.
Decide what your specific research interests are. This is extremely important, because it should also be one of the major determining factors upon which you base your decision as to where you will attend school. Within each field of study, choose two or three different interrelated topics for the same reason that you narrowed down your fields of study to two or three.
Research scholars in each of the major fields you hope study in. Examine recent articles and books in each of the specific research areas you have designated and determine which scholars are currently working and publishing regularly in your field of study. Create a list of these scholars for future reference.
Visit the website of each school represented on your scholar list. You may have to conduct general Internet searches by searching for each scholar by name. If they have a page available at the college or university they teach at, visit the page and obtain their contact information and any other information about their research interests and publications.
Contact each of the scholars on your list. Email them and then follow up with a phone call at a time when they keep office hours. Inquire about their current work and whether they are currently advising Ph.D. candidates. Also ask about teaching assistantships, fellowships and other forms of financial aid to help you make your decision about where to attend school. Follow up with these individuals on a regular basis as you are going through the admission process. This may help you get into some of the programs that you apply to, because these scholars will already be familiar with you and your research interests.
Examine your list of scholars and schools to determine which is the best fit for you. Financial aid and what areas of research you will be able to engage in at that school should be your primary considerations as you make your decision. Don't make any final decision until you have applied to each program and they have made you offers for financial aid and scholarships. Make your final decision once you have received responses from every school.