Coursera Personally I love this website, I have started a couple of courses on it and they are great, more specifically they are very action oriented, you actually feel involved. There are a lot of courses that you can do for free and also do paid courses for free but not a get a certificate for, if you find it useful, they pay for it and get your certificate of completion.
Udemy Udemy has a lot of free content for sure, they also run a lot of great discount offers throughout the year. More importantly you can find established and independent tutors alike on Udemy. From programming to photography to language, you name it and its there.
Symbiosis Centre for Distance Learning (SCDL) One of the largest autonomous distance learning education institute in India. SCDL has, since its inception in 2001, made rapid strides in providing quality education to many students - making it one of the few large and most sought after distance learning institutes of India.
Khan Academy Learn Maths, law, arts, music, programming, take preparation tests online and all these for free. By far I think Khan Academy has more free courses than compared to the others, you should definitely check it out.
Udacity Learn to program a robotic car, create a blog from the co-founder of reddit and much more. A very action oriented website, very concise videos, might not have as much free content, however indeed has some great value to offer. All the websites mentioned here, have their own key points check them all.
Lynda.com This one is my absolute favorite, a gold mine for visual workers, photographers, and filmmakers, graphic designers, matte artists, I mean whichever skill that requires a computer to be used for developing your skill is available on this website to learn. Sure none of it is free but it has a subscription model and you pay monthly, learn as much as you can throughout the month.