Hi there - we at all3dp started two series for 3dModeling in FreeCAD and Sketchup which i'd like to share with you
http://all3dp.com/topic/3d-printing-for-beginners/ for the general overview.
If you have feedback, feel free to contact me directly, also of course if you have a tutorial / printer / newsworthy that needs coverage:
FreeCAD
Part 1
Part 2
Part 3
Part 4
Part 5
Part six will follow after the author finishes his school
Sketchup
Part 1
Part 2