How to wire a two wire thermostat?

Its got two wires... hook them up.

Your question is a complex one so please consider telling us a lot more about your system. Big difference connecting a two wire thermostat to just the heat, as opposed to heat pump and air conditioning system.

Wire A Thermostat (http://www.how-to-wire-it.com/wire-a-thermostat.html)

Are you replacing a two wire thermostat?