Online learning courses

http://shawacademy.com/
https://www.udemy.com/
https://www.edx.org/
https://www.coursera.org/
http://htmldog.com/
https://www.howdesignuniversity.com/
http://www.daveconservatoire.org/
https://www.khanacademy.org/

Sites with coding challenges

Here is the list of sites that provide coding challenges in various languages:
https://www.codewars.com/
https://www.codingame.com/start
http://codegolf.stackexchange.com/
topcoder