It is nice to have some background in the technique, but not necessary at all. I would suggest you watch the tutorial videos and lessons. Then you will have a better understanding going into a lesson, but if not he is always glad to start from the.....well start! Watching the videos makes your time and money worth more since you can understand the basics and get into the details and avoid the easy to make mistakes.
You certainly will leave the session with a great attitude toward learning more and perfecting your craft, and feel much more confident no matter what level you are starting at.