I've been meaning to highlight the Hazel tutorial over at MacOSXScreencasts.com for awhile. I wanted to make it all the way through the tutorial first. I have, and it's worth the $13 price tag.
If you are new to Hazel or consider yourself a novice at automation, this screencast is totally worth buying. By the end, you'll feel very comfortable with using Hazel and get some nice workflow enhancements along the way.
The video quality is great and the material easy to follow. I probably wouldn't recommend it to a Hazel power user, but I think there are few people that would fall into that category. Almost everyone else could benefit from this tutorial.
So, if you want to actually take advantage of that little duster sitting in your menu bar, go get it.