Reasons to Believe

Historical Evidence for Christianity: Includes an article on extra-biblical references to Jesus
The Uncaused Cause: Argument for believing the universe had a cause, also known as the kalam cosmological argument.
The Impossible Faith by J.P. Holding (offsite): Describes the obstacles that would have prevented Christianity from surviving if it were not true
An Argument for the Faith by Glenn Miller (offsite): In Glenn's words, "a slow-paced, low-key argument for the faith" that outlines his own reasons for belief

Fulfilled prophecies in the Bible (offsite) - including prophecies fulfilled in post-Biblical times

100prophecies.org lists many Biblical prophecies fulfilled from 70 AD to today
Fulfilled Prophecy: Evidence for the Reliability of the Bible by Hugh Ross - Lists thirteen prophecies and the estimated odds of their being fulfilled by chance

Why investigate Christianity?
The Four Spiritual Laws, explained for skeptics: Outline of the basic message of Christianity.
Do atheists need God?
What distinguishes Christianity from other monotheistic religions?
Becoming a Christian: How to become a Christian and what to do next.