Training

Here are some resources to help you train for the Olympiad.

Beginner

Michael Penn's Youtube playlist

Junior Olympiads on Art of Problem Solving

Advanced

National competitions on Art of Problem Solving

The IMO Compendium

Evan Chen's website

Yufei Zhao's website

Alex Remorov's Website

Canada IMO Training

Coffin Problems

Many more links on Art of Problems Solving.