Christians can find a vast wealth of resources online. An excellent starting point is Bible Gateway, which allows browsing and searches of twenty different English translations of the Bible. You can find the Bible there in forty-two other languages! The site also contains commentaries on many books of the Bible.
Classic Biblical commentaries can be found at Bible Study Tools and, organized differently, at Classic Bible Commentaries.
Early Christian Writings provides links to more than 150 Christian texts written between 30 and 400 AD. The Christian Classics Ethereal Library includes the writings of the early church fathers, including Tertullian, Origen, and Augustine.
The Internet Christian Library includes historic and contemporary Christian writings of many different kinds. At From Jesus to Christ, you can watch a PBS special on early Christianity and investigate the historical foundations of the faith further. The Thoughtful Christian has study materials on a variety of topics.