The olympiad community welcomes any effort toward organizing an IChO in your country. You can approach the SC in any phase of preparation or decision making, as the main duty of the Committee is to assist organizers in this great task.
The SC has prepared a guideline complete with a checklist that can help you before and during the preparation. Please distribute this document among your coworkers.
A selection of examplary problems was compiled by a working group of the SC lead by Petra Menova; this will be a useful resource for your Scientific Committee for ideas of features to include as they author new problems.