Attached Link: http://poserpython.com

The books I have found most helpful when learning Python where:

Learning Python
M. Lutz and D. Ascher
published by O'Reilly
There are two editions to this one. If you're using P5 get the second edition.

Python Visual Quickstart Guide
C. Fehily
published by Peachpit Press

Python Pocket Reference
M. Lutz
published by O'Reilly
Again two editions, get the second edition if on P5.

After you get some Python programming under your belt get these two:

Python in a Nutshell
A. Martelli
published by O'Reilly

Python and TkInter Programming
J.E. Grayson
published by Manning

TkInter is the extension used most often for building GUIs.

I found it helpful to learn about the regular flavor of Python scripting before getting into PoserPython. PoserPython scripts are mainly regular Python with some calls to PoserPython functions added to access Poser itself. If you've got a handle on Python before getting into PoserPython's methods, it's much easier to see what's going on in the scripts.

I have some scripts in the FreeStuff area and also some at the attached link.