To add to the other answers:
- Если слышен денег шелест - значит, лох пошел на нерест. (If you hear a rustle of money, it means a salmon is going to spawn.)
"Лох" is an old word for a salmon, but nowadays is used as a synonym for a fool. The proverb connects these two meanings. A salmon is an easy prey during the period of spawning.
- Без лоха и жизнь плоха. (Life is bad without fools.)
This is a view on fools as a source of profit.
- Нет понятия "спиздили", есть понятие "проебал". (There is no such thing as "they stole", but there is such a thing as "you lost.")
This phrase is usually used with the addition "в армии" ("in the army") at the beginning of the sentence and means that every soldier is responsible for his own private belongings. The phrase is sometimes used outside the army, too, and shows the mentality that the guilty side is the victim because he made it possible for the crime to happen by not protecting himself and his belongings.
- На дурака не нужен нож. (You do not need a knife to deal with a fool.)
This phrase is originally from a famous Russian cartoon for children, "Буратино", and is used to say that you do not need to use brute force to get from a fool what you want. You can just tell him any lies, and he will buy them. The original song from the cartoon is:
Покуда есть на свете дураки,
Обманом жить нам, стало быть, с руки.
Какое небо голубое,
Мы не сторонники разбоя:
На дурака не нужен нож,
Ему с три короба наврешь —
И делай с ним, что хошь!
Translation: "As long as there are fools, it is practical for us to live by trickery. What a blue sky, and we are not proponents of plunder: You do not need a knife to deal with a fool, since you can tell him any lies and then do with him whatever you want."