There's a lot of material for English learners on YouTube but the problem is sorting out the wheat from the chaff (i.e. the good from the bad - and there's plenty of bad!). JenniferESL is one of the better resources. Jennifer, who is American and an experienced EFL/ESL teacher, has her own channel on YouTube. Here you can find playlists devoted to Grammar, Pronunciation and Common Mistakes. What I particularly like are the clear objectives Jennifer gives for each lesson and the fact that key phrases are subtitled.
The number of views a video gets gives an indication of its quality. The one below got over 40,000!
Tech tip: Create a YouTube account. You can then add videos to your Favorites and subscribe to another user's channel. See the YouTube Help Center for more information.