You have my sympathy in trying to learn modern Archicad on your own. There was a time when that was possible, but that time has passed.
Archicad's "Help" menu presents a number of documents - notably the Archicad "Get Started" and the Archicad "Training Guide."
Interactive Training:
http://www.graphisoft.com/products/archicad/ac10/ITG/
Other books exist, but they aren't strictly for training - they are for problem-solving for various issues.
But the real trick with Archicad is employing lateral thinking, and to properly exploit Archicad, you need an hour with an old hand to show you the ropes/tricks.
Good luck
Dwight Atkinson