Hans Urs von Balthasar’s book ‘Prayer‘ gives a broad theological account of Christian prayer, particularly contemplative prayer. However, it should be noted that the Liturgy of the Hours is at the foundation of Catholic prayer since priests and those in religious orders pray it daily. It’s important to keep this in mind when reading Batthasar’s book.
If one searchs this blog for ‘liturgy’, one will find various postings related to the Liturgy of the Hours, aka Divine Office, aka Breviary. The full four volume edition is more useful than various abbridgements which often wind up distorting the basic nature of the Breviary. In my opinion, lay faithful should also resist the anxiety of the overly scrupulous and feel free to pick and choose from the full Liturgy of the Hours in their daily prayer. This will, in the long run for at least some people, be more useful that trying to do everything all at once, especially if one does not have supporting community praying the daily office.