For noobs to the game;
start with road vehicles. trains are done in a similar way, but learning signals is very complicated.
1) place a bus station in each of a few cities that arent far from each other.
or
place a truck station next to a producing resource, and another one at it's corresponding receiving one.
2) connect the stations or cities with roads
3) build a depot anywhere on that road network
4) go into the depot and buy a bus (or truck type for whatever resource you built for)
5) if its not already open from when you bought it, click your road vehicle you just paid for so it's info window pops up. (if you cant find the vehicle, its parked inside the depot)
6) the little yellow arrow on the vehicle's info window is how you give it directions.
7) when the arrow is clicked, start clicking on stations that are built to put together a direction list for him.
8) should be just the 2 for now. it will auto loop.
9) click the go/drive button on the vehicle window and he will begin following his directions.
10) he will pick up from 1 station and drop off automatically when he visits the second station (or if busses, pick up and drop off at each one)
11) income is made, let him be alone for a bit and watch the stations, if his cycle cant keep up with production, add another vehicle.
note; stations dont react or produce until they are visited for the first time. so that first run to each station is a dry run to enable everything.