Keep an eye on the
Creativelive website. They have live webcasts on various subjects that you can interact with whilst live, and occasionally rebroadcast courses. They are free to watch, though you can pay to download the videos and any resources.
They have had some good Landscape course recently, a
nd have Landscape Photography with Marc Muench on Jan 8+9. Never heard of him, but it costs nothing to have a look. 
They also have a rebroadcast of
The Art of Nature with Art Wolfe on Jan 10+11. I've heard of him.
As a more general Photography course the have
the Fundamentals of Photography 2015 with John Greengo. That's a 5 day course, and I've watched them over the last few years and they have been excellent. I even bought the course a few years ago, but they get updated every year.
Be aware that the times of courses on the site are Pacific time as they are based in Seattle and San Francisco. They are normally broadcast in the UK from 5pm till around midnight, though they are repeated throughout the night and next day till the next live broadcast starts. If you register you can set the courses to reflect your timezone when logged in. You can also enrol for courses, which commits you to nothing, but they send you reminders before any courses start.
Creativelive have also started to do guides to cameras, where they go through all the body features and all the menus during a one day course, and give advice on how and why to set some settings in the camera. They have done
one for the D3*** series. That would have to be purchased to watch though, as I doubt they would rebroadcast that.
As for Youtube, I've found that there is a lot of good information on the
AdoramaTV channel .
I just think they do quality stuff for the most part. I've watched loads of stuff on there over the last few years. 
For Creativelive