Writing a code to trace itinerary road on map

i have a section on a website that i have to write. the concept is that users will have a map and they can choose an itinerary with a starting location and a destination. When they press generate, they should see a route on that map (maybe with written directions also).

The problem is that its the first time i work with maps i tried to research on the subject but found nothing helpful. If you can point me in the right direction i would be grateful. Any tutorial, book , video, ideas.. would be much appreciated

thanks a lot

Ahmad