The Apologetics Index  (Apologetics is the reasoned defense of the Christian faith)
A very extensive and thorough site just stuffed full of apologetics material about religious movements, cults, sects, world religions and related issues.  All material is written to equip Christians to understand and refute the beliefs of those who oppose Christianity.  A very valuable site.  Includes current research about the "Gospel of Judas" and "The DaVinci Code"

   Bible.org (Home of the NET Bible). 
A very extensive site offering excellent articles dealing with questions related to Bible translation, difficult texts, historical backgrounds, etc.  Also contains the full text of the New English Translation (NET) Bible (with over 60,000 translation notes), as well as book outlines, biographies, and free courses in Theology, Hermeneutics, and Church History.

   BlueLetterBible 
The BlueLetterBible might just contain everything you need to really "get into" the Bible.  A completely searchable database… dozens of commentaries… audio/visual files… maps and charts… timelines.. and much more!  Take some time to see what this site offers!

   Creeds of Christendom  
A pretty complete collection of all the important creeds, confessions and catechisms from all the major branches and denominations of the Christian church.  If you want to read what great thinkers of the past thought about the faith, then this is a good place to start.

   Christian Classics Ethereal Library 
A massive online library of classic Christian books for download or browsing.

   Crosswalk.com
Basic study tools and more for your walk with Christ: Several translations, word and phrase search capabilities, Greek and Hebrew dictionaries, daily devotions, prayer chains, discussion groups, guides to Christian music, books, etc.  This site has something for everyone.

   Hall of Church History 
Much more than just history!  Contains the celebrated section "Theology from a bunch of dead guys".  Well worth repeated visits.

   SermonAudio.com 
Over 20,000 sermons in audio format (mp3, wav, etc.)… all completely searchable by Speaker, Subject or Text, and all completely Free.  Can be downloaded and burned to a CD or can be listened to online.  An excellent audio library.

   Vine’s Expository Dictionary of Old and New Testament Words 
William E. Vine’s classic dictionary, completely searchable and linked to other resources, such as Easton’s Bible Dictionary, Nave’s Topical Bible, Torrey’s New Topical Textbook, etc.