Enclosure Design
document every step of your process including materials and fabrication procedures - someone should be able to replicate your process. Consider using videos in addition to images. Show images of your fabrication files.
Controls (electronics)
document every step of your process including products (and where you got them from) and assembly procedures - someone should be able to replicate your process. Consider using videos in addition to images. Be sure to include your electronic schematic diagrams.
Parts & Pieces
This section may not be applicable to all projects. Document any 'finishing touches' you included in your project.