Is it a good idea to contact potential supervisors?
It is certainly a good idea to look at our list of staff and list of suggested PhD topics in order to learn about the areas in which we conduct research, and who is interested in which areas. Nearly everybody maintains a personal homepage that describes their research interests in some detail and provides links to some or all of their publications. Once you have looked at this information, contacting a potential supervisor by email might be useful in deciding how to focus your application or to ask for more information about his/her current research agenda, but it is not required. It is definitely not a good idea to send a vague statement of interest to a large number of potential supervisors, or even to a single individual.