As usual, Jacobus de Voragine's Golden Legend has the basics of Andrew's vita - but many of the episodes so clearly illustrated here don't appear in that compilation. Instead one must turn to the apocrypha for the extended version of the Apostle's life. For medieval audiences, the obvious source was Gregory of Tours, whose Liber de miraculis included a lengthy section cobbled together from assorted 2nd-3rd century Greek texts on the Acts of Andrew. For the background to these texts, see Wilhelm Schneemelcher & Robert McLachlan Wilson (eds) "New Testament Apocrypha: Writings relating to the Apostles; Apocalypses and related subjects", chapter XV. There is also an on-line version of M R James' 1924 translation of Gregory's text at http://gnosis.org/library/actandy.htm.