Electronic Residency Application System is the uniform way to apply to ACGME accredited residencies during your 4th year of medical school. This site has a lot of resources including links to every program participating in the match*. Click the link and scroll down to "ERAS Participating Specialties".
Med Map is an interactive map that allows you to view residency programs in the United States by location. You can filter by specialty and it's a great tool when you are ready to apply for residency!
VSLO stands for Visiting Student Learning Opportunities. This website houses an array of programs participating in accepting other medical students who may be interested in applying to their program or specialty. Use this website to fill your 4th year with away or audition rotations!
Reddit is a social media platform great for resources, stories, and literally anything about medical school. Please just keep in mind that there is a biased community in reddit posters (i.e. high achieving students) and not all posts are made from US MD/DO students (i.e. IMGs, including Canada and the Caribbeans).
Funded Away Rotations for Minority Medical Students (FARMS) Database is a directory of programs offering stipends to students underrepresented in medicine participating in visiting electives.