wxPython is a blending of the WxWidgets (formerly WxWindows) class library for C++ and Python. wxPython can be found at (surprise!) http://www.wxpython.org/ and it has its own wiki there: http://wiki.wxpython.org/. ShowMeDo has a collection of introductory wxPython videos.
wxPython Guide is a thorough tutorial on wxPython toolkit. It can be found on zetcode.com
IgorTamara: WxPython in a good linux distribution is really easy to install, just : apt-get install libwxgtk2.4-python or
MythDebunking: WxPython is hard to install on Unix. You need the right versions of GTK, WxWidgets and WxPython.
Also check the WxDesigner and BoaConstructor.