With very helpful comparisons to Git.

A clickable git cheatsheet showing how to move between different workflow areas (working tree, index, repos)

Junio on the git philosophy of branching.

Indeed, the title says it all.

Nice reference to how the various commands modify HEAD, staging area, and working directory.

Martin Krafft explains how to do a clean git-svn import, rebase a git history on top of it, and convert patches to branches; with commands you can copy-paste. Plus a short bonus lesson on merging. In a Debian packaging context but still useful elsewhere.

A very detailed walkthrough from Martin Krafft on how to maintain a Debian package in git, tracking a git upstream. Includes discussion of branch usage showing examples for topics and integration, with commands you can run. Also the use of tags. Useful even for non-Debian work! From 2007; some git commands may have changed.

How you should format commit messages when using git, but just as good for an version control system.

Using terms like "directed acyclic graph", explains the guts of git. Good for quick overview and reference.

How to manage git commits across multiple repositories, etc.

An excellent description of basic workflow and explanation of git's index.

various git resources as compiled by the folks at 37 Signals