Since Python is such a popular and well-regarded language, there are many high-quality tutorials available on the web. The official python tutorial, written by the inventor of Python himself, Guido van Rossum, is very good.
The Non-Programmers Tutorial For Python by Josh Cogliati is also very good for those with no previous programming experience.
You can go and download a printable Python "cheat sheet" from the Added Bytes website, available here:
Sometimes a good reference book is invaluable. The following books have gotten good reviews from us and our customers:
Learning Python (O'Reilly, 2007)
Python Pocket Reference (O'Reilly, 2005)
Core Python Programming (Prentice Hall, 2006)
Python Power (Course Technology, 2007)
This book would be useful for anyone who finds themselves accessing the Java standard library frequently from Python:
Python Programming with the Java(TM) Class Libraries (Addison-Wesley, 2002)
You can also find the excellent API documentation for the Java standard libraries from Sun here:
Our online forum at http://www.inductiveautomation.com/forum is a great place to go for scripting help. Not only do we, the Inductive Automation staff, monitor it actively, but we have a thriving user community who can help you with any scripting questions.