Hi again,
Well try to start on Youtube, there you’ll find a lot of great example on almost everything in NAV.
Specifically about the changes between the old classic versions and the RTC versions, then that was basically covered with version 2009.
https://www.youtube.com/watch?v=I0Y-XZbSlZk
But youtube have lots more there. If you’re more traditional, then go to Amazon, they also have tons of books on learning NAV.