The federal posters that should be on display for your business vary widely depending on the type of business that you are in. The U.S. Department of Labor has an interactive Poster Advisor tool that will walk you through the steps to determine the posters you will need specifically for your particular business.
In addition to knowing what federal labor posters you should have on hand, you should also visit the Idaho Department of Labor to determine the state labor posters that are required. Your insurance company will provide a workers compensation poster.