What are good representatives for the concepts of endergonic and exergonic?
As you say you are starting with Gibbs free energy, just pay attention to the $\Delta G$ values. Remember that $\Delta G= \Delta H -T\Delta S$ so it doesn't depends only on enthalpy but also on entropy. A process where $\Delta G&lt;0$ is exergonic and in the opposite case it is endergonic.

About the examples we can say that: 


Salts that disolve in water are exergonic processes, $\Delta G_\mathrm{disol}&lt;0$.
Sodium bicarbonate will disolve in vinegar to produce $\ce{CO2}$ (because of the high concentration of acetic acid), it is also exergonic.