Amos 3:7
Surely the Lord GOD will do nothing, but He revealeth His secret unto His servants the Prophets.

Isaiah 46:9-10
Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me, declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure ...

Isaiah 52:6 
Therefore MY people shall know MY name: therefore they shall know in that day that I Am He that doth speak: behold it is I.

ISAIAH
Isaiah prophesied on the birth, life, and death of Jesus, and the Lord used him to reveal many End Times prophecies. A very popular Prophet.

JEREMIAH
Known as the weeping Prophet. He had to tell all the bad news of Babylon. He prophesied during carryout.

EZEKIEL
Ezekiel was a Prophet before and during the carryout. He preached and prophesied at the same time Daniel, Jeremiah, and Habakkuk did. He was visited by angels called cherubim. He also went to heaven and saw the New Temple and new Jerusalem. He was visited by the hand of the Lord much.

DANIEL
Daniel was carried out of Jerusalem (Judah) and chosen by Nebuchadnezzar to live in Babylon under the employ of him. The child was chosen because of his appearance, wisdom, understanding. Daniel refused to eat kings meat, because it would defile him. God took him in, and made him wise in visions and dream interpretation. He foretold of many things including the coming of the Messiah, wars, nations that were to rule. God was with him. He was greatly beloved of God.

HOSEA
Hosea was forced into marriage with a harlot to show the way God feels about Israel's idols when He is the husband. He foretold End Times and many other prophecies.

JOEL
Disaster strikes the southern kingdom of Judah without warning. An ominous black cloud descends upon the land -- the dreaded locusts. In a matter of hours, every living green thing has been stripped bare. Joel, God’s spokesman during the reign of Joash, seizes this occasion to proclaim God’s message. Although the locust plague has been a terrible judgment for sin, God’s future judgments during the day of the Lord will make that plague pale in comparison. In that day, God will destroy His enemies, but bring unparalleled blessing to those who faithfully obey Him.

AMOS
The first prophecy of Amos came two years before the earthquake of Uzziah. He basically spoke of current events but did speak of the End Times a bit.

OBADIAH
Obadiah’s whole prophecy was concerning judgment and punishment of Edom (Esau) for it's mocking of Israel in the day of their calamity.

JONAH
Jonah was reluctant at first, but after a three day stay in fish belly, he changed his mind and preached to Nineveh. The city mourned and fasted. God forgave them but Jonah was angry, for he felt for all he had done, they should not be forgiven. God taught him.

MICAH
Micah prophesied to such kings as Ahaz and Hezekiah. He told of Jesus' birthplace and other events of Jesus. He also wrote reason for time lapse of Daniel's 70th week. He told of End Times.

NAHUM
Nahum basically prophesied against Nineveh.

HABAKKUK
Habakkuk prophesied around the time of the carryout to Babylon. He questioned the Lord's judgment. Later he repented and made a prayer to God.

ZEPHANIAH
Zephaniah spoke of the gathering and the great day of the Lord. Though only three chapters long, he covers the last days.

HAGGAI
Haggai prophesied during the rebuilding of the temple by Zerubbabel. He told the people to continue the rebuild. He also told of Zerubbabel's presence in the end.

ZECHARIAH
Zechariah prophesied during the time the temple was being rebuilt by Zerubbabel. He prophesied much to Zerubbabel and Joshua the high priest. He had many visions of current events, and future, even to End Times.

MALACHI
Malachi was the last Prophet of the Old Testament. He foretold of John the Baptist, the forerunner for Jesus. He foretold mostly future events including Jesus first visit, the cleansing of man by Jesus, judgment, End Times, and a fiery ending with Elijah coming before the dreadful day of the Lord.