In NZ, newly trained local teachers often have references written by their 'mentor teachers' (who supervised the student teachers during classroom practicums). Back in my day (early 90's - eek!) we also had letters written by the Dean of our School of Ed, which basically combined comments from all of our practicums into one document outlining our strengths etc. Schools do look for references from people who have actually seen you teach, so if you are planning on doing any volunteering etc, I would be sure to ask the principal to come in and observe you teach at least one lesson. That way they will be able to refer to what they actually saw you do.
Amy.