Apologetics = (giving a reason, making a defense) (not apologizing!)
Evangelism is like offense and apologetics is like defense. I would rather spend a whole conversation talking about what God has accomplished through Jesus but when someone comes against the message then it’s time for defense.
I would recommend a beginner to start with Jason Lisle’s book or Voddie Baucham’s below.
Every Thought Captive – Richard Pratt, Jr.
Ultimate Proof of Creation – Jason Lisle
Expository Apologetics – Voddie Baucham
Covenantal Apologetics – K. Scott Oliphint
You should consider studying the textual history of the NT and the concept of canon as well. This is not the easiest subject to study but it will be greatly beneficial to you both personally and in your conversations with others. Here are some excellent books that deal with these subjects.
The King James Only Controversy – James White
Canon Revisited – Michael Kruger
The Heresy of Orthodoxy – Andreas Kostenberger & Michael Kruger
The Question of Canon – Michael Kruger
Westminster’s Apologetic Course. Click to launch iTunes link