When I was collecting python related RSS feeds a few months back I came across this wonderful project called PyMOTW by Doug Hellmann
Though one such effort was made by effbot a long time back with a book called Python Standard Library it was on python2.0 after which a lot many changes happened in python standard library. PyMOTW fills this gap by coming up with articles mostly on new modules of python that were included in python2.3 onwards.
Having the through knowledge of what python distribution has by default saves you from reinventing the wheel most of the times. I found my self in such situations a lot many times :)