The Association of the American Medical Colleges (AAMC) has a website that will provide you access to the American Medical College Application Service (AMCAS). This is the portal through which you will eventually submit your application materials. The site also contains a wealth of information including a medical school preparation timeline, information about the Medical College Admission Test (MCAT), admissions requirements, how to prepare for medical school interviews, and how to finance your degree. There is also a search engine for Postbaccalaureate Premedical Programs.
The American Dental Education Association (ADEA) administers the centralized application form for most dental schools through the Associated American Dental Schools Application Service (AADSAS). However, if you want to apply to a dental school in Texas you will use the Texas Medical and Dental Schools Application Service. The dental school application submission period generally opens in June and runs through February, with schools making provisional offers beginning in December. You may also be required to submit additional materials to each school to which you apply. For more information view this YouTube video: What I learned on my Dental School application journey that presents the views of various dental school applicants and see this ADEA timeline which provides an excellent roadmap on what you need to do to prepare for dental school. The Dental Admission Test (DAT) is the exam required to apply to dental schools.
Physician Assistant Programs
Approximately 90% of training programs for the Physician Assistant profession participate in the Central Application Service for Physician Assistants (CASPA). Physician Assistants work under the supervision of a medical doctor and are usually part of a team. PA programs grant either a Masters in Physician Assistant Studies (MPAS), a Masters in Health Science (MHS) or a Masters in Medical Science (MHSc). There are over 220 programs in the US and the application cycle runs from April every year until the following March with program start dates varying by school. You often have to show substantial work experience in a clinical setting and submit additional materials to schools to which you are applying. For example, the UC Davis program requires 1,000 hours of either paid or volunteer work and invites a select group of applicants to apply for UC Davis admissions after the initial CASPA screening process. You can find more information about the profession at the Academy of American Physician Assistants (AAPA).
Masters in Public Health
The Association of Schools and Programs of Public Health (ASPPH) administers the centralized application service called SOPHAS (Schools of Public Health Application Service) for many participating public health schools. SOPHAS has a checklist of requirements that includes a Statement of Purpose and Objectives but even though much of the information is aggregated, including test scores, CV and GPA/grades, you are able to custom write a statement for each institution you are applying to. Sometimes those institutions may ask for a Personal Statement as well, which is the case with UC Berkeley. Make sure to check the requirements for each school/program to which you are applying. For a Masters in Public Health you will required to submit scores from the Graduate Record Exam (GRE).
To apply to Law School you will need to create an account at the website of the Law School Admission Council (LSAC). The LSAC website has a link to the Credential Assembly Service (CAS) which is where you will eventually submit your transcripts, letters of recommendations and LSAT score when you are ready to apply. But the site also provides you with a great deal of preparatory information about law school. There are search engines to look for appropriate schools, an overview of the application process and information on Forums in various cities where you can talk to representatives from many schools.