My husband found this great tool online:

http://www.montevideobus.com.uy/

It's like a Google map, where you zoom in/out/east/west, etc.  You mark your origin point and destination on the map and then click on "buscar recorridos" and it shows you which bus(es) can take you on that route, how many stops, etc.  Very cool!
Now we can feel less lost in our new city!

Feliz Navidad to all!