Whether or not you should begin EMDR treatment is a joint decision you need to make with your therapist. EMDR is not suitable for every client at any given time. If your clinician was properly trained in the method s/he knows the client selection criterion. You might ask your clinician to review them with you.
While there are a number of books now available to give you an overview of treatment, there is no substitute for personal interaction. Basically, tell your clinician what you need in order to feel comfortable making a joint decision. You need enough information to give an informed consent to any form of treatment.