There are many groups in Facebook with only one goal: to learn English. Many students go there to share their knowledge, to share their ideas about English.
Sometimes, there are English teachers who teach English online, they use facebook because it's as simple as blogging, and many English students can join easily. Also the daily number of people on facebook is huge. Nowadays, more than 90% of Internet users go to facebook.
You can also go to youtube, you can find many videos to learn English. In fact learning English with videos is also very powerful.
What are waiting now? go to facebook right now and start to learn English!!