For a Shapeoko 3, the official instructions for current machines are at:
Homing switch instructions: http://docs.carbide3d.com/shapeoko-faq/shapeoko-3-limit-switch-installation/ or
Additional links, information and videos are at: Shapeoko 3: Assembly Instructions.
c.f., Photographic Shapeoko 3/XL/XXL Assembly Instructions (unfortunately incompleat) --- intended as a supplement to the official instructions
- Assembly overview (SO1)
- Shapeoko 2: http://shapeoko.github.io/Docs/
- Shapeoko 3 Launch Edition / Sparkfun Stepoko: http://carbide3d.com/files/so3manual.pdf --- this is useful as a reference for better understanding the machine, its assembly, and component parts. Please note that some versions of the instructions have an error on pg. 9 where eccentric nuts are indicated to be placed along the top of the plate --- they should actually go on the bottom.