As of 2016, Electrical-Knowhow.com and HighPerformanceHVAC.com have instructions for air conditioning wiring. Electrical-Knowhow.com provides a detailed series of articles on air conditioning systems with wiring diagrams and explanations of how air conditioning systems generally work. HighPerformanceHVAC.com has an article on how to wire an air conditioner with five wires.
Electrical-Knowhow.com has a free course titled "Electrical Wiring Diagrams For Air Conditioning Systems" in multiple parts. There are schematics of typical air conditioning systems, instructions for wiring, images and links to relevant informational articles both within and outside the site.
HighPerformanceHVAC.com has a comprehensive table of thermostat wire terminations, a description of where each wire goes and what it controls, a detailed diagram for a five wire air conditioner and related resources and links.