An Introduction to the Gospel of John - Introduction. Covers the authorship, date, origin and destination, its purpose and also talks about its relationship with the other Gospels. In outline form. - http://www.bible.org/page.php?page_id=1328
Let John Be John: A Gospel for Its Time - Essay by James Dunn reviews the characteristics that set John apart from the Synoptic Gospels. - http://resources.theology.ox.ac.uk/library/data/pdf/THD0080.pdf
The New Era in Johanine Interpretation - Recent trends in understanding John's Gospel, article by David Rensberger. - http://resources.theology.ox.ac.uk/library/data/pdf/THD0081.pdf
The Johannine Literature Web - Resources for the academic study of the gospel and letters of John. By Felix Just. - http://catholic-resources.org/John/index.html
The Fourth Gospel and John's Epistles - Web site links and a bibliography of books and journal articles related to the Johannine Literature. By Armand J. Gagne Jr. - http://www.fourthgospel.com/