As we read individual books of the Bible, it is helpful to have an overall understanding of them. This can done by first of all reading the book in it's entirety, preferably in one sitting. The following are some other helps in understanding individual books of the Bible.
First, we should understand to whom the book is written. Let us look at Ephesians 1:1 "Paul, an apostle of Jesus Christ by the will of God, to the saints which are at Ephesus, and to the faithful in Christ Jesus." Now if we look at Ephesians 1:7 we read "In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;" Who has forgiveness of sins? Well we read in Ephesians 1:1 that the book of Ephesians was written to "the saints which are at Epesus, and to the faithful in Christ Jesus." So it is the saints in Christ Jesus that have the forgiveness of sins. Now let us look at Isaiah 1:1 where we read, "The vision of Isaiah the son Amoz, which he saw concerning Judah and Jerusalem in the days of Uzziah, Jotham, Ahaz, and Hezekiah, the kings of Judah." Here we see that the vision that Isaiah received is going to concern Judah and Jerusalem. All of the Bible is for us, but not all of the Bible is to us.
Something else that might be helpful in reading individual books of the Bible is their relationship to the chapters in the book of Isaiah. There are 66 books in the Bible and 66 chapters in Isaiah. As we read individual books of the Bible in light of their corresponding chapter in Isaiah we see a definite correlation.
As we approach the Pauline epistles we see their order given to us in II Timothy 3:16 "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness." Emphasis mine. Doctrine is first in order and we see this in the book of Romans, one of the chief sources for church doctrine and sometimes called the "constituion of Christianity." Next is reproof and we find that in the books of I & II Corinthians. In the Corinthians epistles the Apostle Paul had to reprove the Corinthian Church for divisions, fornication and carnality. After that we have correction, which we see this in the book of Galations. Paul had to correct the Galations concerning the legalizers who had crept in teaching a salvation by law and grace and that that a justified believer must keep the law. Lastly there is instruction in righteousness and we find this epitomized in the book of Ephesians. Here we have the the church at it's highest spiritual state and some of the deepest truths of the Word of God are reavealed. We also see in II Timothy 3:16 the structure of the Pauline epistles. Paul's epistles begin with doctrine, end in practical instruction with reproof and correction if necessary in between.