One of the coolest way to learn stuff by yourself is to jump to an OpenCourseWare and get the lecture materials. But sometimes I found I really hard to natvigate OpenCourseWare like MIT one. David Wiley has developed an online utility called OpenCourseWare Finder, based on del.icio.us direc.tor, which can list and narrow down courses by choosing multiple tags. The AJAX system makes the navigiation much easier and faster.
For the list of free courses, This is what it fetches:
View more information: https://www.lifehack.org/articles/lifehack/list-and-find-opencourseware-courses.html