So, I've begun to be active in an affiliate group of my university's alumni association. Their handbook is a good one, and here's the list on recruiting volunteers that I found to be quite well put.
Do not assume that people are too busy. Sometimes busy people like to be busy. Be a friend and make sure they are welcomed. Do not belittle the job. Do not make it sound too easy. Give the job a name, define a timeframe, provide guidance and relay expectations. Do not add to the responsibilities during the job. Make sure the task is achievable and the goal is obtainable. Speak the language of the person you are trying to recruit. Ask yourself, what do we do that would be of interest to them? If you are not personally committed, assign someone else to do the recruitment. Always recruit volunteers on the basis of the service to clients, not to the needs of the [organization]. People work for people, not things. Tell people what they will do, how long they are expected to do it, and who will benefit. Remember that you are trying to remove people's reasons to say NO, not force them into volunteering. Never use guilt when trying to recruit. Be honest and upfront with people when recruiting. Do not minimize the work or time required.