Do you remember MOSAIC? The script that allows Blender to export 3d scenes, to Pixar RiSpec and related renders. At the web site Blender to RenderMan, the autor of the script has posted a full set of tutorials, showing how to use the script.
Here a message by Ted Gocek, admin of Blender to RenderMan, with a short description of the tutorials:
Recently the developer of MOSAIC has been writing full tutorials on how to use the python script, some of them step by step instructions. The new cvs version is more advanced, with more control over the RiSpec in a single script than any other script made before hand, making this the best option out there with the current release builds of Blender, Aqsis and Pixie.
There are 12 tutorials total, complete with screenshots.
If you want to check out the tutorials, visit the Blender to RenderMan web site.