A good tip in your book would be to state that AppleScript Language Guide is the first book, after that they should read, or refer to sections in it directly! And get rid of the kittens. (I hope they transform into tip boxes over time!
Other things I’d like to see would be:
Debugging, logging facilities
This is imporatant when starting with AppleScript to overcome hurdles.
Like other languages, it needs logging facilities, so you don’t fumble in blindness. Things may differ when run stand alone, than in the editor, as the environment is different.
log, and handlers that log to the console, when run from an app or as a script.
Usage of Xcode for development, if you can’t afford Script Debugger, which you should
If you manage to do that, I don’t unless I do something in ASStudio or ASObjC, which I don’t at the moment, but then I get the ability to step through code. and inspect variables in the debugger, not a replacement for Script Debugger, which is the singular most important thing to buy/have, in order to get up to speed.
The usage of try on error end try for catching errors, either with a blunt log statement inside when run from the ScriptEditor, or passing the error number and message over to a dialog box, or sending it to a logfile, (you can make Console.app pop up when there are errors), is very useful. Reading and understanding the error messages too.