Where can I find the planned and flown paths for certain flight routes?
Yes, depending..... 
On FlightAware.com you can see the routing of a flight after it's flown, and the same flight the next day will probably file for the same route.

On FltPlan.com you can find typical routes that a plane is likely to be cleared on and have actually been cleared on over time. Pretty accurate, but you probably need flying skills to interpret it, or get training on understanding routing, airport ICAO codes, nav fixes, departures arrival and enroute routing.