The word "See" here adds emphasis to what follows. Alternate translation: "Look, I send" or "Listen, I send" or "Pay attention to what I am about to tell you. I send"
Sheep are defenseless animals that wolves often attack. Jesus is stating that people may harm the disciples. Alternate translation: "as sheep among people who are like dangerous wolves" or "as sheep among people who act the way dangerous animals act"
Jesus is telling the disciples they must be cautious and harmless among the people. Alternate translation: "act with understanding and caution, as well as with innocence and virtue"