1) Jesus starts this sermon angry at abusive leadership. In John 9, Jesus heals a blind man on the Sabbath. The leadership of Jerusalem (Pharisees and priests) ought to respond by thanking God and helping the blind man start a new life. Instead, they insult him and expel him from the synagogue since he insists that his healer must be from God. John 9:35-41 is a pivot passage - it wraps up the conflict of John 9, but also begins Jesus' denunciation of the Pharisees and Temple leadership. John 10 is thus both a defense of Jesus' status as the true leader of Israel and an attack on the abusive leadership of Jerusalem.
2) It's common for Christians to quote John 10:10, "The thief comes only to kill and steal and destroy" as a reference to Satan. However, all the "bad guys" in this chapter are the leaders of Jerusalem, not Satan. NT scholar Craig Evans points out that in other Jewish literature of this period, "thief" was a common term used for the priestly leadership of Jerusalem.
3) In John 10:1-9, a number of distinctive phrases are intended to remind the reader of Numbers 27:15-23, the appointment of Joshua. These similarities are even more obvious when you read them in Greek. in Num 27, Joshua is appointed as the next shepherd of the nation. His appointment is affirmed by Moses and by the high priest before all the people of Israel. By referring to this passage, Jesus compares himself to Joshua (who has the same name as Jesus, after all), and suggests that the priests and Pharisees of his time should also affirm Jesus' leadership.
4) In John 10:8-16, a number of distinctive phrases are intended to remind the reader of God's condemnation of the leaders of Israel in Ezekiel 34. In Ezek 34, God is the good shepherd, and all the other leaders of Israel are described as bad hired shepherds who steal, kill, and scatter the sheep. Ezekiel 34 also talks about God's appointment of "David" as a good shepherd. Jesus' use of this passage from Ezek 34 shows that he was claiming the status of both good shepherds from Ezek 34 - David and God.
Like most other scenes in John, this passage reveals Jesus as the source of life to those who believe. This passage also contains a warning: the Temple leadership (both political and spiritual) of Jesus' day cannot provide life, but in fact steals life. As John most likely wrote after the destruction of the Temple, he intended this to be a timeless warning: no other leader can provide genuine life as Jesus can.