http://hginit.com, a wonderfully written Mercurial-tutorial by Joel Spolsky from Fog Creek Software (Trello). Especially when you come from Subversion like me, Joel made me think several times “Ohhh, yes, you’re right!”:
Subversion always gives you this horrible dilemma. Either the repository is full of bugs because it includes new code that was just written, or new code that was just written is not in the repository.
Recently I work more and more with products from the guys at Atlassian, like Jira and Confluence. In 2010 they bought the company BitBucket, a Mercurial hoster, and a little bit later its Mac client SourceTree. It is even freeware by now, and I must say it is a very good alternative to terminal.