See the book webpage
The list of notebooks below contains links to versions you can view online via nbviewer. (Check out this link and also the gallery for lots of cool examples of notebooks and books/papers written in this format.)
If you want to modify something in a notebook and re-execute, you will need to download the notebook (or find it in the Class GitHub Repository, in the codes directory).
You will need a recent version of IPython in order to run an IPython notebook (recently renamed Jupyter notebooks since they also support Julia, R, and other languages besides Python).
Notebooks can be found in $AM586/codes/ if you want to run the notebook.
If you want to easily run notebooks without installing any software, you might try Using SageMathCloud.