Lost in the Cosmos is a site that outlines the main arguments relating to the existence of God.

TSAS Religion Philosophy & Ethics A level Web Site

Medieval Source book - Anselm on the existence of God

The Ontological Argument from Whitworth College

Richard Swinburne and the existence of God from 'Leadership U'

William Paley and the design argument from the Victorian Web

John Henry Newman and the Moral argument