Try giving Greg Nelson a call at 1800-435-4373. He is a vice president at Landstar and a good freind! He will steer you in the right direction. Best of luck and keep us posted how it works out.
Another avenue is to go to a large full service truck stop ,try to get all of the industry publications. Truckers News and some of the others usually have an advertisement on some oufit trainng you to become a broker.These ads usually are in the last few pages. I would be very careful and really check them out for references before I sent them any $.