It took me a while to figure out how to write a hook for commit-messages in Windows to send an E-mail to project users. For some reason, SVN is not shipped with an example of how to do this for Windows, although there is a Python script for Unix. Finally, I stumbled across http://commitmessage.tigris.org/, which worked well when installed with Python. To save others trying to figure out how to do this, the book, notes, and www should be updated to reference the http://commitmessage.tigris.org/ project, where references appear to the mailer.py and commit-email.pl (which I can't even find in the Windows install).
Original issue reported by philmat11