In order to do a PhD, you will be expected have a background in the subject. Usually students who have previously completed a Masters are accepted into PhD programs. However, this is not always the case. If you are able to show and prove exceptional academic ability, proficiency or interest in the given subject, you may be offered the opportunity to complete a PhD program without a related Masters degree. Prerequisites will depend upon both the subject and the organization through which you are completing the PhD.
During the course of study, you will need to meet a number of requirements that are the backbone of any PhD. These requirements include the discovery of novel or new findings, which must be written to a publishable standard. You will need to display a thorough understanding of your subject, including the methodologies used as research tools. Finally, you need to present all of these findings and methodologies in a thesis. The thesis needs to be well and clearly presented and include all of your findings and display them in a scientific manner, culminating in a discussion and conclusion of results.
Any PhD student is required to meet with a supervisor. The number of meetings required will be largely up to the student and supervisor. If you have little previous experience in academic research, it is a good idea to meet frequently so the supervisor can guide your work. On average, a student and supervisor might meet once per month.
The first two years of any PhD are largely spent compiling and researching reading materials, doing basic lab work and recording the findings. These years are mostly spent doing laboratory or practical experiments.
The third or final years of your dissertation will mostly be spent compiling all of the researched materials and putting them together in your dissertation or thesis. During the course of these years, you will probably choose to meet your supervisor more frequently to discuss the presentation and composition of the thesis. During the final year or years, you may also be asked to orally defend your thesis in front of a panel of professors or supervisors.