I've just attended a great course on Introduction to Solving Biological Problems with Python taught by Graham Ritchie and Ines de Santiago in Cambridge University. The great thing is that the course materials are available for free, so you can learn from them by yourself.
Getting the IPython notebooks
The course materials are available as IPython notebooks from the course github repository. You just need to go to the github repository, click on one of the files (eg. Introduction_to_python_session_1.ipynb) and click 'Raw' in github, and then save the raw file.
Opening one of the IPython notebooks
You'll then need to install IPython on your computer to view then.
When you have downloaded the different files, you can view them in IPython (on a Mac) by typing for example: (you need to type this in the directory where you have saved the notebooks).
% /usr/local/homebrew/bin/ipython notebook
This brings up the IPython notebook interface in a web browser.
You can then choose the notebook you want to view from a list.
On my Mac, to run an IPython cell, you need to press Shift+Enter.
If you open a new IPython notebook, you can insert comment lines by pressing CTRL-M and then M.