Tut+ of Envato does a great job on this. Like SM, they also give out free tutorials, but they go a lot more technical and not limited to designing. They also have a premium section of their site which does quite well according to Collis Taeed (sp?).
Great example, I actually subscribe to Net Tuts+ and think that Collis and Vahid really hit the niche of how-to type website spot on by building the Envato networks.