Mike Kruger, author of Canon Revisited: Establishing the Origins and Authority of the New Testament Books (Crossway, 2012) and the forthcoming The Question of Canon: Challenging the Status Quo in the New Testament Debate (IVP, 2013), has a helpful series on the New Testament canon, linked below, "designed to help Christians understand ten basic facts about its origins. This series is designed for a lay-level audience and hopefully could prove helpful in a conversation one might have with a skeptical friend."
Here are the posts:
"The New Testament Books are the Earliest Christian Writings We Possess"
"Apocryphal Writings Are All Written in the Second Century or Later"
"The New Testament Books Are Unique Because They Are Apostolic Books"
"Some NT Writers Quote Other NT Writers as Scripture"
"The Four Gospels are Well Established by the End of the Second Century"
"At the End of the Second Century, the Muratorian Fragment lists 22 of Our 27 NT Books"
"Early Christians Often Used Non-Canonical Writings"
"The NT Canon Was Not Decided at Nicea—Nor Any Other Church Council"
"Christians Did Disagree about the Canonicity of Some NT Books"
"Early Christians Believed that Canonical Books Were Self-Authenticating"