Susan Sink's book describes every illumination in The Saint John's Bible, explaining the intent of the artists and providing her own reflections. She also includes useful indexes: a timeline of the project, a list of each artist's specific contributions to the project, and locations of all marginalia, including the correction bees and birds. This work was originally in three separate volumes, consolidated into one in 2013, and the one-volume edition is the best one to use.
Patella is a Benedictine monk and a Professor of New Testament at Saint John's University. He was a member of the Committee on Illumination and Text that advised Donald Jackson and his team on the process of illumination. Patella catalogs the meaning of every illumination in this Bible, and he also explores how a biblical scholar views this project. This is a very useful book for understanding the broader hermeneutical framework of this project.