Here are a number of sources for online classes that are free!
You’ll find software tutorials here, along with a collection of more than 1000 practice tests and skills tutorials (SAT, GED, LSAT, ASVAB, Citizenship, etc); a comprehensive job search and career guidance system; and more. You'll need your library card number and PIN to access this database.
Coursera offers over 300 courses taught by professors from highly rated universities all over the world. Courses last four to twenty weeks and range in topic from Public Speaking to Nuclear Science. Many courses feature video lectures and online discussion forums, and utilize quizzes and assignments to enforce student learning.
The OpenCourseWare Consortium is a collection of free course materials from over 13,000 courses taught at over 250 universities around the world. Available course materials may include video lectures, readings, and exams with solutions.
Created by Harvard and MIT, edX offers interactive online courses in subjects including business, history, engineering, and literature. These courses are free and are taught by professors from universities like UC Berkeley, Georgetown, and UT Austin. Students have the opportunity to audit a class or complete assessments to earn a Certificate of Mastery.
A program of Goodwill Industries, GCFLearnFree.org® creates and provides quality, innovative online learning opportunities to anyone who wants to improve the technology, literacy and math skills needed to be successful in both work and life
Open Yale Courses
Open Yale Courses provides free and open access to a selection of introductory courses taught by distinguished teachers and scholars at Yale University. The aim of the project is to expand access to educational materials for all who wish to learn.
MIT OpenCourseWare (OCW) is a web-based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.