Usage models:
[:WorkingPractices] describing several ways to use Mercurial
How to handle [:MultipleCommitters]
[:CommunicatingChanges] describes the various ways Mercurial can exchange [:ChangeSet:changesets]
How [:SymbolicLinks] work
Setup and Automation:
[:PublishingRepositories] and [:ServerInstall] describes various ways to make your code visible to the world
[:MercurialOnSourceforge] explains how to serve Mercurial [:Repository:repositories] using Sourceforge.
Features:
[:NamedBranches] gives an introduction to this feature
See also: [:FAQ], [:TipsAndTricks]