This package installs the hg executable in /Library/Frameworks/Python.framework/Versions/Current/bin. This directory may not be in your shell's search path. The MacPython installer will have created an entry in .profile for it but if your shell doesn't use .profile you'll need configure it yourself or create a symlink from a directory already in your path.
Documentation
+Visit the Mercurial web site and wiki
+There's also a free book, Distributed revision control with Mercurial
+Reporting problems
If you run into any problems, please file a bug online: