Python is an interpreted programming language that reads like pseudo-code. It has interpreters on just about every extant computer and is integrated into many open source projects such as Blender (a 3D modeling tool) and Panda3D (a video game engine). Python can be used as an imperative language (do this, then do that) or an object-oriented language (create X, create Y). A python program can just be a set of commands, or a large modular object oriented project. Selected useful Python links
python.org: the main python web site.
A Byte of Python: an online book on programming using Python. Intended for those with little or no programming experience.
One Day of IDLE Toying: an online tutorial to the IDLE Python development environment.
How to Think Like a Computer Scientist: an online textbook covering basic programming concepts.
Beginning Python for Bioinformatics: overview of bioinformatics applications and how you can build them using Python.
Python Tutorial: the tutorial that comes with the Python documentation and is updated with every release. Intended for programmers.
Instant Python: a quick crash course on Python for programmers.