The book of Psalms has 150 psalms. They were sung and prayed in the temple and in the homes of Israel, and Christians have used them for over two thousand years.
Three kinds of psalms
Psalms of praise thank God for who he is and what he has done, for example Psalm 100 and Psalm 103. Psalms of lament bring pain, anger and doubt straight to God, for example Psalm 13 and Psalm 22. Psalms of trust say that God can be trusted, like Psalm 23 and Psalm 121.
You may say everything
What perhaps surprises most is how honest the psalms are. They are not tidy. The psalmist may ask why God is so far away. That gives us permission to be honest in our own prayers.
How you can use them
Read a psalm slowly, preferably aloud. Pause at a word or a sentence that strikes you. Make it your own prayer. If you do not know what to pray, a psalm can lend you the words.
The words of the Psalms are available in several translations here. Try the Berean Standard Bible or Åpen Bibel if you want to hear them in a new way.