The Association of American Medical Colleges Careers in Medicine (AAMC-CiM) provides a wide variety of career development tools including self assessments, career exploration and decision making exercises, and residency application guidance (CV and personal statement writing, letters of recommendation, interviewing skills). Their advised timeline includes completing their self assessment as a T1/T2 and using their Choosing Your Specialty and Specialty Indecision Scale exercises as a T3. Careers in Medicine is an excellent and reliable resource and should be consulted through all years of medical school.
You will need your AAMC username and password to access CiM. This is the same login information you used for AMCAS and will need for ERAS.