I've published a Healer Mini Guide for Priest and Mystic. It's available here and will be updated periodically.
Whether you are a beginner playing TERA for the first time, or a veteran to one class hoping to pick up another class, the guide will provide you with a general idea of how Priest and Mystic work and how to better play these two classes.
Please check it out and I hope it provides some useful information 
