you can start using python as a general programming first
http://www.python.org/
http://www.tutorialspoint.com/python/
http://www.learnpython.org/
or you can try specific book or tutorial regarding python for GIS Software, like python for ArcGIS,
you can find it on sharing area, or request if you didnt find it
here :
http://www.gisarea.com/index.php?/forum/5-rs-gis-sharing-area/
look in book and tutorial section