This page contains a list of websites and books which I think will be helpful for those who want to learn more about math olympiads and those who want to hone their problem solving skills. New material is coming out all the time as this page will always be a work-in-progress!
- IMO Official Website: The official website for the International Mathematical Olympiad. A centralised resource for finding IMO problems and results.
- Art of Problem Solving: How do I even begin to describe this website? It is a must-visit for anyone interested in math olympiads. They have a huge forum with discussions on just about every topic you could imagine, including problems from recent competitions. They also have an in-house bookstore and hold math classes that you can enroll for. I can’t vouch for the bookstore and the classes as I’ve never used them myself, but the forum is definitely something you should check out.
- Brilliant: A problem solving community where users can both pose problems to the community and solve problems that others have posed. Problems are not limited to olympiad math– other topics include science and computer science.
(Note: I have not included books which are compendiums of past olympiads.)
- How to Solve It, by George Pólya: A slim volume describing some general principles a student can use to approach math problems. Has some good questions that one can ask when approaching any problem. Even though it was written back in the 1940s, the principles laid out remain valid today.
- Problem-Solving Strategies, by Arthur Engel: A classic must-read/must-do book back in the day.
Other websites of interest (not directly related to math olympiads)
- Detexify: Want to include a math symbol in your document but don’t remember its code? No fear: draw your symbol here!