Psychology is a science, bound by the use of the scientific method in order to obtain and analyze real-world data about humans and animals. Psychology is not just the study of the mind, but also of any and all behaviors affected by the mind, which is basically everything we do [see previous post on BEHAVIOR]. Psychologists are trained to be objective. This is not easy, as we are humans studying other humans, often motivated by our own life experiences.
Psychologists identify concepts that they wish to study and seek ways to generate operational definitions of such concepts that lead to testable and measurable circumstances. While overt behaviors are the easiest to objectively quantify, covert behaviors, with a solid operational definition, can be studied vicariously through overt measurement and effective research methods (such as a survey or interview). Psychologists make logical inferences, not leaps of faith, when proposing hypotheses and formulating theories.
Psychic: the proposed ability to "read" another person's mind and/or tap into a real of mysticism that is beyond a humans standard five senses--sight, sound, touch, taste, smell. A psychic typically deals with things that cannot be quantified, thus making it extremely difficult, if not impossible, to study in a scientific manner. Psychics have a tendency to "read" a person's future, discerns their thoughts nonverbally, "commune" with other-worldly phenomenon such as spirits.
Psychologists are NOT trained to read a person's mind. If you come across a psychotherapist who seems to be able to "read" you, it is most likely a case in which the therapist is highly experienced and really good at making fairly accurate inferences based on that experience. One of the reasons studies are replicated and a body of research builds around a specific area (e.g. the work of Elizabeth Loftus on eye-witness testimony) is that we begin to detect patterns and then test out our ideas to confirm the existence of those patterns. Please do not ask a psychologist to read your mind. Do not expect all psychologists to be highly intuitive, especially people who are just starting out in the field. From studies of intuition (yes, it can be scientifically, objectively studied), we know that it is actually a skill that develops over time. Some people are more intuitive than others mostly because they are more observant and analytical than others. They combine information in more unique ways, also.
Incidentally, not all psychologists are psychotherapists, either. True, the majority of psychology graduate students enter a clinical psychology program. However, a quick trip over to the American Psychological Association list of divisions will show you that there are many pathways a psychology major can take, even at the undergraduate level. I, for one, decided early on in my academic career that I did not want to be a therapist or a counselor. That is one of the many reasons I chose Industrial/Organizational psychology for my undergraduate focus and graduate studies.
Psychiatrist: an individual with a medical degree (M.D.) whose medical training focused on the mind and the defects and disorders associated with the mind. NOTE: Some psychiatrists also hold an academic doctorate in clinical psychology, so their training is a bit more extensive.
Psychotherapist: an individual holding a doctorate (typically Ph.D. or Psy.D.) whose graduate focus was on mental defects and mental disorders and therapies associated with treatment of such. Without an M.D., this person CANNOT prescribe medication [a couple states in the U.S. are/were considering altering this restriction, though].
Psychologist: an individual with a graduate degree (M.S., M.A., Ph.D., Psy.D., Ed.D., etc.) whose graduate school training focused on a specific area of psychology. Not all psychologists need a doctorate to "practice" in their field. That is dependent upon the area you enter. For example, an animal behaviorist typically needs only a master's degree in order to be considered ready for employment or as a consultant in the field.
So, here are two assumptions to avoid when meeting a psychologist: the person can read your mind; the person is a therapist. The first one will almost always be wrong. The second one, while statistically within your favor, is still a risky bet to make.