Who is a person who shows the way?

This depends on the meaning of "the way":

• guides lead you to physical destinations or thru exhibits
  
• pioneers discover opportunities and problems into new lands
  
• gurus, swamis and clergy as well as philosophers show the way thru spiritual and emotional matters
  
• counsellors give guidance for emotional problems
  
• teachers and trainers show the way through educational ,material
  
• traffic cops and sigbneb guide you thru traffic problems
• trainers and coaches show the way to athletic performance