Can we all work on this? Somehow nobody seems to treat writing crappy commits (messages like "work since Tuesday" or "it works now") like they would writing crappy code. Version control is fundamental to our job.
It's funny -- I think this is where some of the conflict lies. With git, you can do a bunch of commits with crappy comments and then, when you are ready to publicize it (push, whatever), you can use rebase to pretty up your commit history. In other words, I take the analogy of "crappy commits" to "crappy code" a step further: the commit history is another document that is to be presented to other developers; make it helpful!
Most developers learn by example. I've looked for resources on using vcs properly but the few that existed weren't very good. A great resource would be a showcase for a collection of great commits. It doesn't exist as far as I know unfortunately.
as davvid says, the git project is an excellent place to start. The git project inherited a lot of its practices from the linux kernel project, but they are different enough to make looking at both interesting.
The archive for the git list is at [1].
The other great thing to look for is a well designed standard, with examples, for how a commit message should look. Most everyone who uses a standard uses The Standard* [2], so I would suggest you do the same.
* Except that many projects don't require the sign-off