For those who are not yet Christians in a vital, personal sense, but are willing to think carefully about the deeper issues of life and the Christian faith, the following resources may be helpful:

Sermons
http://www.sermonaudio.com/source_detail.asp?sourceid=christreformedpca
The Wondrous Cross  (Galatians 6:14)
How Many Doors? (John 10:1-30)

On-line publications/PDF’s
http://www.chapellibrary.org/listbytitle.html
(These are just a few suggestions from a vast number of resources at this site.)
What Is A Biblical Christian by Albert N. Martin
 The Bible; Advice to Seekers; All Comers to Christ Welcome all by Charles H. Spurgeon
Alive or Dead? by J. C. Ryle

Hard-copy books and booklets:
Ultimate Questions by John Blanchard –a comprehensive and very clear presentation in booklet form.

Basic Christianity by John R. W. Stott-a classic presentation in a small paperback

Evidence that Demands a Verdict and More Evidence that Demands a Verdict by Josh McDowell two lengthy tomes filled with evidence supporting the historicity and reliability of scripture and the specific claims of Christ and events of Christ’s life, e.g., the resurrection.

Websites:
Ligonier Ministries
http://www.ligonier.org/
Though not a specifically evangelistic or apologetics ministry, there are still many solid and clear resources here for those thinking seriously about the deeper issues of life and the Christian.

Answers in Genesis
http://www.answersingenesis.org/home/area/qa.asp
This website focuses mainly  on issues relating to the Bible and science, evolution, etc., it also has articles and links relating to other, broader aspects of the Christian faith and gospel

Renew Your Mind
http://www.renewyourmind.org/Apologetics%20101.htm