Spoke Size / Spoke Length Database - What size spokes do I need?

Wheelbuilding is almost as contentious as religion. Someone's always going to wade in with their spoke stretch/round down/reaching end of thread opinions, to which they're entitled.

I'm sticking with this, if wanting to be absolutely sure of things:

• measure ERD of rim in 4 places, and take an average.
  
• run hub/rim measurements in 3 different spoke calcs, and take an average.
  
• round up or down to nearest spoke available within 1mm.
  
  

But there are more experts on forums like Weight Weenies than this one.