i dunno know what exactly you’re looking for regarding passes, but any of the CG forums discuss things you can do with each layer. For example, last night I was reading about photo-realism of making a hatch, http://www.blendernation.com/2007/02/10/hard-surface-texture-painting/ and he used the AO pass with a multiply mix to outline the edges to show him where to use a scratchy texture brush…all of these are easily doable in Blender. You wont find a site that applies all of the possibilities of CG using Blender; it’s more like you have to understand the concepts and then know/use Blender enough to know how to do it using Blender.