guide
/ɡaɪd/
Someone who guides, especially someone hired to show people around a place or an institution and offer information and explanation.
The guide led us around the museum and explained the exhibits.
A document or book that offers information or instruction; guidebook.
A sign that guides people; guidepost.
Any marking or object that catches the eye to provide quick reference.
A device that guides part of a machine, or guides motion or action.
A spirit believed to speak through a medium.
A member of a group marching in formation who sets the pattern of movement or alignment for the rest.