This morning i've stumbled on (Blender Nation) on 2 free Cycles e-books written by Joakim Tornhill:
1- The Beginners guide into Cycles, the procedural way:
https://docs.google.com/document/d/1zk2mWLxdRZmNLi6uww32LvGUJUQimrPFFKaoFbZ7_Jc/edit
2 - Procedural wear from A to Z in Blender
https://docs.google.com/document/d/1fWaorEppgDpnP08XbTKipR7S0JdARZgoMI9ApmCmBa4/edit
I hope you enjoy this free Cycles E-books :-)
EDIT: 1st link fixed (thanks for the feedback)
