Multiple sign up pages?

Any idea how I can create two different sign up pages with each page requiring different input from the user?

Basically, I'm working on a medical site that will have three types of profiles: nurses, doctors and patients. The first sign up page will be for the patients, and second one will be for the doctors/nurses and they will need to specify if they are a nurse or a doctor.

My php skills are very basic. Is there a module that can do most of the work for me?

Thanks in advance,
Nimi.