Thoughts on several wines given to me

I am very new to the wine drinking world. My mother-in law gave us several bottles last week and we are wondering if we should drink them or save them. Anyone know the value of these wines??

1. Mouton-Cadet Bordeaux Blanc 1981
2. Beringer Chenin Blanc 1978
3. Charles Fournier Chablis Superieur - unknown year.

Thanks in advance for any help.

Charles