What NEC section, if any, covers an owner wiring their own home?
In general, the NEC (or any other code for that matter) specifies how the work must be done, but does not touch on who the work must be done by. The who is covered by local statutes (whether city, county, or state). Permits and licenses are entirely state, county, or city constructs, and various jurisdictions utilize different versions of the NEC.