Basic timeline:
August --> register for ERAS
September - October --> apply to programs, register for NRMP
September - October --> early interviews for NRMP specialties (very few programs interview this early)
November 1st --> Dean's letter/MSPE goes out
mid-November - January --> most interviews
February --> late interviews (some programs)
I took off early November to the end of January, because I have to write a thesis and I finished my requirements, but most other applicants I met took off December or January and had electives with flexible scheduling (or forgiving attendings) the other months. Remember to take time to study for Step 2.