That will be fast, lol:
0) If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
(duh)
1) Energy can neither be created nor destroyed. It can only change forms.
2) (basically, energy can go from high to low, but not low to high (ex: energy can go from a hot surface to a cold one, but not the other way around))
3) As temperature approaches absolute zero, the entropy of a system approaches a constant minimum.