This series is summarised from Fee G, Stuart D. How to Read the Bible for all its Worth (3rd ed). Grand Rapids: Zondervan, 2003.
Who are these strange men and women? What on earth are they talking about? And why are they relevant today? Nowhere in the Bible do we need more help with interpretation than in the prophetic books!
The Prophets comprise 16 books – four major (Isaiah, Jeremiah, Ezekiel and Daniel) and twelve minor. They are only minor in length and not in significance! Many of the most important statements from the Old Testament (OT) are found in the so called 'minor' prophets. For instance, 'The righteous will live by faith' comes from Habakkuk;  it is quoted in both Romans  and Galatians. 
who are the prophets?
The 16 OT prophetic books were written between 760BC and 460BC. Earlier ones such as Amos were written during the kingdoms of Israel and Judah. Some were written around the destruction of their respective capitals Samaria (722BC) and Jerusalem (587BC) and others during or after Judah's exile in Babylon, such as Malachi. They range from Daniel – who became rich and influential, to Amos – a despised shepherd. Most of them had a hard time: Jeremiah was thrown into a water cistern; Hosea had to marry a prostitute; and Ezekiel had to lie on his left side for 390 days and his right side for 40 days.
This period contains such a concentrated set of written oracles (individual prophetic utterances, each given on a particular occasion) because it was a time of unprecedented religious disobedience and social upheaval within Israel. Changes in the global power balance (between the regional superpowers Egypt, Assyria, Babylon and Persia) were occurring as never before and a fresh wave of God's word was needed.
speaking God's word
The mark of the prophet was that they were called by God. Nearly all were reluctant to accept the divine call. If someone presumed to take the office upon himself, it was cause to question whether he was a false prophet.  The prophet was God's spokesperson, so phrases like 'This is what the Lord says' appear regularly.
Prophets were like ambassadors from the heavenly court. They were neither radical social reformers nor innovative religious thinkers; they merely reinforced what had already been revealed in the covenantal law given to Moses.
mediating for God
God announced the enforcement of his covenant with Israel through the prophets. The prophets pronounce the blessings and curses that come from keeping or disobeying the law.
the nature of prophecy
The spoken words of these 16 prophets, out of many in ancient Israel, were chosen to be recorded. As a collection of spoken oracles, the chronological order of the longer books (particularly Jeremiah) is not neat. This can make the Prophets difficult to understand, made worse by their choosing to speak in poetic verse! Their spoken oracles are also structured in different forms, such as 'the lawsuit': a summons, charge, evidence and verdict are presented. In 'the woe', an announcement of distress is followed by a reason for it, and a prediction of doom. It's worth bearing these conventions in mind as you seek to understand the Prophets.
the meaning of prophecy
We should not be looking at the Prophets just to predict the future! The meaning is almost always grounded in the immediate future of Israel, Judah and the surrounding nations. Statistically, less than 5% of their messages specifically describe the new covenant age, less than 2% is messianic, and less than 1% concerns events yet to come in our time. To understand the Prophets, we must look back mostly on times that for them were to come, but for us are past.
the problem of history
Being up to 2,770 years removed from the religious, historical and cultural life of ancient Israel we often have no idea what they are referring to and why. For this reason, a Bible handbook can be immensely helpful. These explain historical settings and help you get to grips with passages.
It is important to understand the context in which an oracle was spoken in order to avoid misinterpretation and misapplication. Consider Hosea 5:8-10. When you learn that it refers to war between Israel and Judah in 734BC, the meaning of this verse becomes clearer: 'Judah's leaders are like those who move boundary stones. I will pour out my wrath on them like a flood of water.'  It refers to Judah capturing territory, but subsequently facing judgment for breaking the covenant through warring with their brothers. Understanding how any prophetic passage related to events at the time can help immensely with interpreting it.
I hope that you will be inspired to read the Prophets for yourself! You can build a better understanding by reading the corresponding chapter in How to Read the Bible for All Its Worth. It goes on to consider the second step of interpretation – hermeneutics – the 'application question' that is the mark of any good Bible study!