I took the Motorcycle Rider Program offered by the University of Illinois, http://www.mrp.uiuc.edu. The one I took was for two wheels but it has a lot of valuable info for riding any type of motorcycle. You can also take a course just for trikes but I believe it may be less widely offered. Upon successful completion of the course you will get a card that you take to the DMV and receive your Class M license because the written and skills tests are part of the course. Plus, many insurance companies will give you a discount for the course.