Keep in mind that most poetry is written in the language of emotion in which feelings are uttered. To convey themselves, the authors often use symbolic language and may exaggerate. In addition, they may also try to express their feelings or impress their audience by using some kind of pattern or rhythm.
Most of the poems in Psalms were written as songs and were intended to be sung with a stringed-instrument accompaniment. In this period of history, singing was a part of temple worship services and public events, such as funerals, marriages, and other celebrations.
Many of the psalms do recognize their author such as, King David, Moses, Solomon, Asaph (David's musician), and Levite priests (the sons of Korah). But there are many that are anonymous.
The book of Psalms is quoted more times in the New Testament than any other Old Testament book. The Hebrews divided the 150 psalms into five separate books. In today's Bible they would be divided as such: 1) Psalms 1-41; 2) Psalms 42-72; 3) Psalms 73-89; 4) Psalms 90-106; 5) Psalms 107-50. At the end of each division, the break is marked with a doxology, or formal declaration of God's power and glory. The last Psalm is itself a doxology, using the Hebrew Hallelujah, or 'Praise ye the Lord', at its beginning and end, as well as the word praise eleven other times.