The organisers' official site is iaio-official.org — competition page, syllabus, past paper and results.
1. Know the format
IAIO has a paper-based Scientific Round (maths and algorithms behind machine learning) and a code-based Practical Round. Read the competition format and syllabus first — the ten topics tell you exactly what to study.
2. Work the past paper
The IAIO 2024 Scientific Round test is the best guide to the style of questions. Time yourself and write full solutions.
3. Study the syllabus systematically
Work through the ten topics in order — each one builds on the last. For every topic, aim to be able to (a) explain the idea in plain words, (b) do the maths by hand on a small example, and (c) implement it in a few lines of Python. Round 1 draws on AI concepts, maths and logical reasoning; Round 2 and the AU Camp go deeper into the full syllabus.
Schools running their own preparation groups are welcome to contact the IAIO Australia Committee.
4. Python and tooling
The Practical Round is hands-on model development. Comfortable Python plus numpy, pandas and scikit-learn is the baseline; the Australian Olympiad resources at IOAI Australia · How to Prepare and Resources cover the same ground.