The University of Durham holds the family's Stainer originals.
See the Wikipedia Article and the Encyclopedia Brittanica Article for his life.
In addition, Hyperion Records has a write up, as does Choraline.
John Stainer, a Life in Music, by Jeremy Dibble, Boydell Press, Woodbridge, 2007.
John Stainer and the the musical life of Victorian Britain, by Peter Charlton, David and Charles, Newton Abbott, 1984.
Surge On! Stainer Centenary Snapshot, David Pennant ed, Pennant Publishing, 2001, contained family history. Its contents are on this website as articles.
Sheet Music selection