Links
The Bible teaching ministry of Dr. John MacArthur. Download over 3,000 sermons for free.
The Bible teaching ministry of Dr. John Piper. Download and watch sermons and articles online for free.
Mars Hill Church is in Seattle and Headed up by lead Pastor Mark Driscoll. This is an amazing website with tons of video and audio downloads—including free music downloads.
Seminary level teaching with Dr. R.C. Sproul via video and audio.
Bible Study Tools
www.BlueLetterBible.org
This is the best online bible study tool I have found. This site contains original language tools, commentaries, bible searches, multiple translations, The Treasury of Scripture knowledge (my favorite), and much more. This site is a great help for preparing a sermon or serious bible study.
Look up you questions about the bible by chapter and verse. If you have a question about a specific verse this site might just have the answer. There are a bunch of theological articles also!
Links For Defenders Of The Faith
Tons of short videos addressing the most common objections to the Christian Faith. Topic include: investigating God, investigating Jesus, investigating the Bible, Evolution, the Da Vinci Code and much more
The ministry of James White. Tons of debates, video, radio archives, and articles on theology, cults, & world religions. Very smart guy!
Answers to all your questions on the topic of Creation and Evolution. You will not find a more complete site on this topic.
Evangelism Training
This ministry is dedicated to seeking and saving the lost and training Christians how to share their faith biblically. Very good stuff!
Info on Mormons
www.mrm.org
Articles on the Mormon Chruch.
Watch fantastic videos online for free. I especially recomend The Bible vs. The Book of Mormon and DNA vs. The Book of Mormon.
Amazing film proving that Joseph Smith was a false prophet. View free online. Must see!
Info on Jehovah’s Witnesses
Great info on the false teaching and prophecies by the JW/Watchtower organization.
www.DesiringGod.org 
www.MarsHillChurch.org
www.ligonier.org
www.BibleQuery.com
www.aomin.org
www.AnswersInGenesis.org
www.bcmmin.org
www.MormonChallenge.com
www.TowerToTruth.net