I found So You Want to Be an Apologist, a good post giving advice for wannabe defenders of the faith.  James Holding gives the following excellent advice, with short descriptions.

  1. Be a master of a few trades and not a jack of all trades.
  2. Acquire patience and prudence.
  3. Don’t worry about not having answers to everything — and not having them right away.
  4. Read the works of the opposition. Don’t shun the works of those who may ideologically disagree with.
  5. Read as broadly as you can so that you can "cross fertilize" ideas.
  6. Feel free to leave other issues to those who are "expert" — and try to consult with them if possible.

He also gives advice for those who really want to make a profession of it:

  1. Making it a professional venture means risk and investment.
  2. Find a church that will support your mission.
  3. Get credentialed.