About Mercurial: The Definitive Guide.
1. Reading the book
Mercurial: The Definitive Guide, by Bryan O'Sullivan, is a freely-licensed book about the Mercurial revision control system.
Home page: https://book.mercurial-scm.org/
Read it online https://book.mercurial-scm.org/read/
The source code is available to the adventurous.
The epub version for ebook reading devices.
2. Supplemental information
The book covers Mercurial through version 1.0, which predates a number of important features that you can read about here:
The summary command
The resolve command
The rebase extension
4. See also
Mercurial repository: https://bitbucket.org/hgbook/hgbook