MIT has been a pioneer in offering courses online free of charge!
There are numerous graduate and undergraduate courses with lecture notes, assignments and solutions, projects and examples, exams and solutions, online textbooks, multimedia content, image galleries, OCW scholar and study group.
You will find the regular introductory, intermediate, and advanced theory courses. But you will also find other interesting courses such as Economics and Psychology, Economic applications of game theory, Field Experiments in Economics, Networks, Industrial Organization and Public Policy, Government Regulation and Industry, Economics and E-Commerce, Competition in Telecommunications, Economics Research and communication, Energy Economics, Economics of Education, Economic History of Financial Crises, Capitalism and its critics, the challenge of world poverty and many more!
Click at MIT Open Course Ware and it will take you to the Department of Economics with a list of available courses. Enjoy the ride!