Holy Week is the last week of Jesus' life before his death and resurrection. The Gospels slow down here, and so does the Church.
Jesus prayed the Psalms that week. Crowds sang them as he entered Jerusalem, he quoted them in the temple and at the table, and he prayed them from the cross.
Each day pairs a psalm with the part of the story it belongs to. Take them in order if you can, but any day is open whenever you need it.
The last days
From Palm Sunday to Wednesday: the King enters his city, clears the temple, teaches, and is betrayed.
The three days
From the Last Supper to the tomb: the table, the cross, and the long silence of the Sabbath.
Easter
He is risen. The psalm the crowds sang on Sunday is sung again, with its meaning finally clear.