Home inspectors in Washington State are licensed and required to abide by guidance identified in WAC 308-408C-020.  The standards of practices include twelve mandatory provisions governing the conduct of home inspectors.   

In addition, state guidance outlines what areas and to what standards they should be inspected.  In the video at http://www.youtube.com/watch?v=LGBe1fPrwYA an overview of procedures dealing with structures, exteriors, roofs, plumbing systems and electrical systems is provided.

If you are interested, the home inspection process as required by state guidance, you may want to view this video and one previously recorded.