|Image © Graphisoft|
Your starting point should be the actual announcement.
Next up, the ArchiCAD channel on YouTube. A number of clips have been uploaded already and they'll give you a very good idea of what's new. Check back for more videos in the coming days. Better still, subscribe to the channel.
If you're interested in seeing how ArchiCAD has progressed over the last few years, this chart has a matrix of features from v.14 to v19.
Finally, here's the story behind the ArchiCAD 19 signature building by Bond Bryan Architects.
From what I can see, there are no template-shattering features this time, which is a bit of a relief actually. Instead, we see a number of useful enhancements across the board. Enjoy.