I've heard good things about the book, "Hello World! Computer Programming for Kids and Other Beginners", It's a first book on programming using Python. While it appears to be aimed at kids, I've heard some adults have found it to be a good gentle introduction as well.
See my other post about free on-line college level classes, for info on Computer Science 101. This class is due to start April 23rd, 2012. Hopefully it will be a good resource for people with no formal CS background.
The same professor, Nick Parlante, developed a class on Python for Google:
"Welcome to Google's Python Class -- this is a free class for people with a little bit of programming experience who want to learn Python. The class includes written materials, lecture videos, and lots of code exercises to practice Python coding."
- Mark Pilgrim's Dive Into Python, and Dive Into Python 3, which are both available freely on-line, or can be purchased as regular print books. The original DiveIntoPython.Org site seems to have been pulled down. I'm not sure what's going on with this. This book seems to be a good intro for programers, though there are some experienced Python People who feel there are some problems with this work.
- The Python Wiki has a good list of Python for Programmer resources.
- The Python Tutorial on the main Python Documentation (docs.python.org) site is also pretty good.