Between Two Worlds

If you're looking for good introductions to or explanations of presuppositional apologetics--what it is, what it isn't, how it works, why it's necessary--you may want to check out these articles by K. Scott Oliphint and John Frame. (Oliphint, by the way, thinks it's time to abandon the term "presuppositionalism" once for all. I tend to agree, since it it is so often misunderstood.)