NumPy http://docs.scipy.org/doc/numpy/reference/
SciPy http://docs.scipy.org/doc/scipy/reference/
Stackless http://www.stackless.com/wiki
MatPlotLib http://matplotlib.org/contents.html
PIL http://pythonware.com/library/pil/handbook/
MLPy http://mlpy.sourceforge.net/docs/3.5/
PyMC http://pymc-devs.github.com/pymc/
Orange http://orange.biolab.si/docs/latest/
PyBrain http://pybrain.org/docs/
SciKit Learn http://scikit-learn.org/stable/user_guide.html
PyWin32 http://sourceforge.net/projects/pywin32/files/
PyWinAuto http://code.google.com/p/pywinauto/
PyPI http://pypi.python.org/pypi
50 Modules http://www.catswhocode.com/blog/python-50-modules-for-all-needs
Python 2.7 http://docs.python.org/2/