With accent marks:
Береги́ пла́тье снову, а честь смо́лоду.
Start taking care of the dress while it's new, and of your honor while you are young.
This saying is about the morals and acceptable social behavior. Once you lose your honor, you can't bring it back.
Other Russian proverbs
The eyes are scared, but the hands are doing.
Eggs don't teach the chicken.
The apple never falls far from the tree.
The quieter you go, the further you'll get.
Without labor, you can not even catch a fish in the pond.
Appetite comes with eating.