Lesson #12 is an introduction to Blender UV Texture mapping procedures. It also focuses on the Blender Sculpting tool.
Suggested Texbook Readings:
Review Chapters 5.4 and 3.27 of the John Blain "Complete Guide to Blender Graphics" UV Texture Mapping and Sculpt Mode (pages 114-117 and 75-84)
There is no lesson 12 PDF tutorial. Spend time experimenting with UV Texture mapping and with Blender sculpt mode.
Lesson 12 - 12B - Rocket Steam Locomotive Modeling (Optional)
Lesson 12 - 12C - Rocket Steam Locomotive Animation (Optional)
Add a Multiresolution modifier to the default cube. Use Blender's Sculpting tools to model a head something like shown in this image. (Variation) Add a sculpted body to the head object.