I found tutoring to be a helpful way to solidify my understanding of the topics and I enjoy seeing others make those previously elusive mental connections. Tutoring is a great way to help your peers/colleagues and earn a little money.
A couple of points, as others have indicated do not let it interfere with your studies and performance on your exams. Your primary objective is learning the material, and doing well in school. The money on the side is nice, but should not take precedent over your first priority. Second, make sure it is okay with your school. As others have mentioned, the school sometimes even has a peer tutoring program. Barring that, my only concern is some schools explicitly prohibit, in the student handbook, any type of employment during medical school. While you could certainly run your tutoring empire under the radar and be fine, it opens you up for issues and disciplinary/institutional actions should anyone decide they don't like you. A simple "that's fine" from your Dean take the risk away.
Enjoy!